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Author name code: dere
ADS astronomy entries on 2022-09-14
author:"Dere, K." 

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Title: The Temperature and Emission Measure Distribution in the
Quiet and Active Solar Corona: A Bayesian Approach
Authors: Dere, Kenneth P.
2022ApJ...930...86D    Altcode: 2022arXiv220317086D
  The reconstruction of the differential emission measure (DEM) from
  observations of spectral line intensities provides information on
  the temperature distribution of the emission measure in the region
  observed. The inversion process is known to be highly unstable,
  and it has been necessary to provide additional constraints, such as
  requiring that the DEM should be smooth. However, this is a nonphysical
  constraint. The goal of this analysis is to make an empirical
  determination of the ability of a set of emission-line intensities to
  constrain the reconstruction. Here, a simple model is used, by means
  of a Markov Chain Monte Carlo process, to arrive at solutions that
  reproduce the observed intensities in a region of the quiet Sun and
  a solar active region. These solutions are compared by means of the
  reduced chi-squared. The conclusion from this analysis is that the
  observations are only capable of constraining a model consisting of
  four temperature-emission measure pairs plus a determination of the
  standard deviation of the model from the observed line intensities. A
  more complex model with five temperature-emission measure pairs does
  not improve the fit and leads to parameters that are irrelevant. A
  more general conclusion is that the information content of a set of
  observed emission lines is limited with respect to the determination
  of the emission measure distribution.

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Title: CHIANTI—An Atomic Database for Emission Lines. XVI. Version
    10, Further Extensions
Authors: Del Zanna, G.; Dere, K. P.; Young, P. R.; Landi, E.
2021ApJ...909...38D    Altcode: 2020arXiv201105211D
  We present version 10 of the CHIANTI package. In this release, we
  provide updated atomic models for several helium-like ions and for
  all the ions of the beryllium, carbon, and magnesium isoelectronic
  sequences that are abundant in astrophysical plasmas. We include rates
  from large-scale atomic structure and scattering calculations that
  are in many cases a significant improvement over the previous version,
  especially for the Be-like sequence, which has useful line diagnostics
  to measure the electron density and temperature. We have also added
  new ions and updated several of them with new atomic rates and line
  identifications. Also, we have added several improvements to the IDL
  software, to speed up the calculations and to estimate the suppression
  of dielectronic recombination.

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Title: Quiet Sun electron densities and their uncertainties derived
    from spectral emission line intensities
Authors: Dere, Kenneth P.
2020MNRAS.496.2334D    Altcode: 2020arXiv200604184D; 2020MNRAS.tmp.1785D
  The goal of this paper is to apply statistical methods to
  determine electrons densities and their errors from measurements of
  density-sensitive line intensities in the quiet Sun. Three methods are
  employed. The first is the use of L-function plots to provide a quick
  visual assessment of the likelihood that a set of line intensities
  can provide a robust estimate of these quantities. A second methods
  involves a χ<SUP>2</SUP> minimization together with a prescription
  for determining the regions of statistical confidence in addition
  to the best-fitting value. A third method uses a Bayesian inference
  technique that employs a Monte Carlo Markov Chain (MCMC) calculation
  from which an analysis of the posterior distributions provide estimates
  of the mean and regions of high probability density. Using these three
  methods, observations of extreme-ultraviolet spectral lines originating
  from regions of the quiet Sun have been analysed. The quantitative
  χ<SUP>2</SUP> minimization and MCMC sampling provide results that
  are generally in good agreement, especially for sets of lines of ions
  that have L-function plots that suggest that a robust analysis might
  be possible.

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Title: Latest updates to the CHIANTI atomic database
Authors: Young, Peter R.; Dere, Kenneth P.; Del Zanna, Giulio; Landi,
   Enrico; Sutherland, Ralph
2019AAS...23431402Y    Altcode:
  CHIANTI is a database of atomic data parameters and a software
  package for computing the radiative emissions from optically-thin
  astrophysical plasmas. CHIANTI is freely available to the community
  (<A href="http://chiantidatabase.org">http://chiantidatabase.org</A>),
  and is very widely used in the Heliophysics and Astrophysics
  communities. The papers describing CHIANTI have been cited over
  3500 times in the 22-year lifetime of the project. <P />Version 9 of
  CHIANTI was released in March 2019, and this presentation summarizes
  the new updates and highlights important applications. The key change
  for CHIANTI 9 was the implementation of a new method to account for
  recombination and dielectronic capture in the level balance equations
  through new, two-ion models that fully capture the state-to-state
  transitions between ions. The models are needed for the calculation
  of X-ray satellite lines and, for the first time, enable density
  sensitivity to be modeled. <P />A number of the standard atomic
  data-sets have been updated, including recombination rates for several
  important coronal iron ions. New software routines have been written
  for computing the differential emission measure of a plasma, and for
  computing the response functions of the Atmospheric Imaging Assembly
  on board NASA's Solar Dynamics Observatory .

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Title: CHIANTI—An Atomic Database for Emission Lines. XV. Version 9,
    Improvements for the X-Ray Satellite Lines
Authors: Dere, K. P.; Del Zanna, G.; Young, P. R.; Landi, E.;
   Sutherland, R. S.
2019ApJS..241...22D    Altcode: 2019arXiv190205019D
  CHIANTI contains a large quantity of atomic data for the analysis
  of astrophysical spectra. Programs are available in IDL and
  Python to perform calculation of the expected emergent spectrum
  from these sources. The database includes atomic energy levels,
  wavelengths, radiative transition probabilities, rate coefficients
  for collisional excitation, ionization, and recombination, as well
  as data to calculate free-free, free-bound, and two-photon continuum
  emission. In Version 9, we improve the modeling of the satellite
  lines at X-ray wavelengths by explicitly including autoionization
  and dielectronic recombination processes in the calculation of level
  populations for select members of the lithium isoelectronic sequence
  and Fe XVIII-XXIII. In addition, existing data sets are updated,
  new ions are added, and new total recombination rates for several Fe
  ions are included. All data and IDL programs are freely available at <A
  href="http://www.chiantidatabase.org">http://www.chiantidatabase.org</A>
  or through SolarSoft, and the Python code
  ChiantiPy is also freely available at <A
  href="https://github.com/chianti-atomic/ChiantiPy">https://github.com/chianti-atomic/ChiantiPy</A>.

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Title: The CHIANTI atomic database
Authors: Young, P. R.; Dere, K. P.; Landi, E.; Del Zanna, G.; Mason,
   H. E.
2016JPhB...49g4009Y    Altcode: 2015arXiv151205620Y
  The freely available CHIANTI atomic database was first released
  in 1996 and has had a huge impact on the analysis and modeling of
  emissions from astrophysical plasmas. It contains data and software
  for modeling optically thin atom and positive ion emission from low
  density (≲10<SUP>13</SUP> cm<SUP>-3</SUP>) plasmas from x-ray to
  infrared wavelengths. A key feature is that the data are assessed
  and regularly updated, with version 8 released in 2015. Atomic data
  for modeling the emissivities of 246 ions and neutrals are contained
  in CHIANTI, together with data for deriving the ionization fractions
  of all elements up to zinc. The different types of atomic data are
  summarized here and their formats discussed. Statistics on the impact
  of CHIANTI to the astrophysical community are given and examples of
  the diverse range of applications are presented.

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Title: CHIANTI - An atomic database for emission lines. Version 8
Authors: Del Zanna, G.; Dere, K. P.; Young, P. R.; Landi, E.; Mason,
   H. E.
2015A&A...582A..56D    Altcode: 2015arXiv150807631D
  We present version 8 of the CHIANTI database. This version includes
  a large amount of new data and ions, which represent a significant
  improvement in the soft X-ray, extreme UV (EUV) and UV spectral
  regions, which several space missions currently cover. New data for
  neutrals and low charge states are also added. The data are assessed,
  but to improve the modelling of low-temperature plasma the effective
  collision strengths for most of the new datasets are not spline-fitted
  as previously, but are retained as calculated. This required a change
  of the format of the CHIANTI electron excitation files. The format
  of the energy files has also been changed. Excitation rates between
  all the levels are retained for most of the new datasets, so the data
  can in principle be used to model high-density plasma. In addition,
  the method for computing the differential emission measure used in
  the CHIANTI software has been changed.

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Title: ChiantiPy: Python package for the CHIANTI atomic database
Authors: Dere, Ken
2013ascl.soft08017D    Altcode:
  ChiantiPy is an object-orient Python package for calculating
  astrophysical spectra using the CHIANTI atomic database for
  astrophysical spectroscopy. It provides access to the database and the
  ability to calculate various physical quantities for the interpretation
  of astrophysical spectra.

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Title: CHIANTI 7.1: a new database release for SDO data analysis
Authors: Young, P. R.; Landi, E.; Del Zanna, G.; Dere, K. P.; Mason,
   H. E.
2013enss.confE..58Y    Altcode:
  Version 7.1 of the CHIANTI atomic database was released in October 2012
  and contains a number of improvements to better model data returned by
  the AIA and EVE instruments on board SDO. Specifically the models for
  the important iron ions Fe VIII to Fe XIV have been greatly expanded,
  yielding many thousands of new transitions in the 50-170 angstrom
  range that enable the irradiance spectra obtained by EVE to be modeled
  more accurately. A lack of available atomic data meant that the AIA 94
  angstrom channel was not well modeled at low temperatures in earlier
  versions of CHIANTI. New data for Fe VIII, Fe X and Fe XIV added to
  CHIANTI 7.1 give important contributions to the channel and greatly
  improve comparisons with theory.

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Title: CHIANTI—An Atomic Database for Emission Lines. XIII. Soft
    X-Ray Improvements and Other Changes
Authors: Landi, E.; Young, P. R.; Dere, K. P.; Del Zanna, G.; Mason,
   H. E.
2013ApJ...763...86L    Altcode:
  The CHIANTI spectral code consists of two parts: an atomic database
  and a suite of computer programs in Python and IDL. Together, they
  allow the calculation of the optically thin spectrum of astrophysical
  objects and provide spectroscopic plasma diagnostics for the analysis
  of astrophysical spectra. The database includes atomic energy levels,
  wavelengths, radiative transition probabilities, collision excitation
  rate coefficients, ionization, and recombination rate coefficients,
  as well as data to calculate free-free, free-bound, and two-photon
  continuum emission. Version 7.1 has been released, which includes
  improved data for several ions, recombination rates, and element
  abundances. In particular, it provides a large expansion of the
  CHIANTI models for key Fe ions from Fe VIII to Fe XIV to improve the
  predicted emission in the 50-170 Å wavelength range. All data and
  programs are freely available at http://www.chiantidatabase.org and
  in SolarSoft, while the Python interface to CHIANTI can be found at
  http://chiantipy.sourceforge.net.

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Title: Recent Developments with the CHIANTI Atomic Database for
    Astrophysical Spectroscopy
Authors: Dere, Kenneth P.
2012AAS...22020802D    Altcode:
  The CHIANTI atomic database for astrophysical spectroscopy maintains
  an assessed set of atomic data that are necessary to calculate emission
  from ionized plasmas that exist throughout the universe. As new atomic
  data becomes available, it is added to the CHIANTI database in order
  to improve the accuracy of data already in the database, to extend the
  range of spectral lines that can be reproduced or to develop new ions
  that are not already in the database. <P />Version 7 of the database
  was recently released (Landi et al., 2012). This included several new
  ions and a wide range of updated ions. A Python interface to CHIANTI,
  ChiantiPy, was developed to complement the existing IDL interface. A
  web application, based on ChiantiPy, was also developed that allows the
  user to make spectral calculations using the Chianti database directly
  from a web browser. <P />Version 7.1 is expected to be released in
  2012 and is expected to include updated atomic data for existing ions
  and the develop of new ions. Ionization equilibria will be updated
  based on new calculations of dielectronic recombination for some
  isoelectronic sequences.

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Title: CHIANTI—An Atomic Database for Emission Lines. XII. Version
    7 of the Database
Authors: Landi, E.; Del Zanna, G.; Young, P. R.; Dere, K. P.; Mason,
   H. E.
2012ApJ...744...99L    Altcode:
  The CHIANTI spectral code consists of an atomic database and
  a suite of computer programs to calculate the optically thin
  spectrum of astrophysical objects and carry out spectroscopic plasma
  diagnostics. The database includes atomic energy levels, wavelengths,
  radiative transition probabilities, collision excitation rate
  coefficients, and ionization and recombination rate coefficients,
  as well as data to calculate free-free, free-bound, and two-photon
  continuum emission. Version 7 has been released, which includes
  several new ions, significant updates to existing ions, as well as
  Chianti-Py, the implementation of CHIANTI software in the Python
  programming language. All data and programs are freely available at
  http://www.chiantidatabase.org, while the Python interface to CHIANTI
  can be found at http://chiantipy.sourceforge.net.

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Title: Recent Progress with the CHIANTI Atomic Database for
    Astrophysical Spectroscopy
Authors: Dere, Kenneth P.
2011AAS...21813402D    Altcode: 2011BAAS..43G13402D
  The first version of the CHIANTI atomic database for astrophysical
  spectroscopy was released in 1997 and the most recent version in
  2009. Recent progress with CHIANTI will be described. <P />Based on
  the ionization rates developed by Dere (2007) and the radiative and
  dielectronic recombination rates of Badnell and colleagues, a new set
  of ionization balance calculations has been calculated. These show
  some substantial difference from previous calculations. <P />A suite
  of Python programs, ChiantiPy, has been developed to allow users to
  use the CHIANTI database to calculate spectral line and continuum
  intensities in an object-oriented manner. This package is also the
  basis for a developmental web server that can show the results of
  specifically requested calculations through a user web browser. <P
  />The direction of future work with CHIANTI will be outlined.

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Title: CHIANTI - an atomic database for emission lines. IX. Ionization
    rates, recombination rates, ionization equilibria for the elements
    hydrogen through zinc and updated atomic data
Authors: Dere, K. P.; Landi, E.; Young, P. R.; Del Zanna, G.; Landini,
   M.; Mason, H. E.
2009A&A...498..915D    Altcode:
  Aims: The goal of the CHIANTI atomic database is to provide a set of
  atomic data for the interpretation of astrophysical spectra emitted by
  collisionally dominated, high temperature, optically thin sources. <BR
  />Methods: A complete set of ground level ionization and recombination
  rate coefficients has been assembled for all atoms and ions of the
  elements of H through Zn and inserted into the latest version of the
  CHIANTI database, CHIANTI 6. Ionization rate coefficients are taken from
  the recent work of Dere (2007, A&amp;A, 466, 771) and recombination
  rates from a variety of sources in the literature. These new rate
  coefficients have allowed the calculation of a new set of ionization
  equilibria and radiative loss rate coefficients. For some ions, such
  as Fe VIII and Fe IX, there are significant differences from previous
  calculations. In addition, existing atomic parameters have been revised
  and new atomic parameters inserted into the database. <BR />Results:
  For each ion in the CHIANTI database, elemental abundances, ionization
  potentials, atomic energy levels, radiative rates, electron and proton
  collisional rate coefficients, ionization and recombination rate
  coefficients, and collisional ionization equilibrium populations are
  provided. In addition, parameters for the calculation of the continuum
  due to bremsstrahlung, radiative recombination and two-photon decay are
  provided. A suite of programs written in the Interactive Data Language
  (IDL) are available to calculate line and continuum emissivities
  and other properties. All data and programs are freely available at
  http://wwwsolar.nrl.navy.mil/chianti

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Title: The Coronal Mass of Solar Active Regions
Authors: Dere, Kenneth P.
2009SPD....40.3702D    Altcode:
  The material contained in coronal mass ejections (CMEs) that originate
  from active regions is believed to be provided by the mass in the
  active region itself. This loss of mass is exhibited by coronal
  dimmings. Previous estimates of the lost mass have depended on
  assumptions about the volume or density of the ejected material. The
  Extreme-ultraviolet Imaging Spectrometer (EIS) on Hinode has the ability
  to measure both emission measures and electron densities and provide
  a better measure of the coronal mass in active regions. <P />The
  technique for determining the coronal mass from EIS measurements is
  described and applied to several active regions. The mass lost during
  a CME eruption is calculated and compared to measurements of the mass
  of a typical range of CMEs. One of the questions that can be addressed
  is whether a CME accumulates or loses mass during its passage through
  the heliosphere.

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Title: CHIANTI Version 6.0 - Inclusion of Ionization and Recombination
    Rates
Authors: Dere, Kenneth P.; Landi, E.; Young, P.; Del Zanna, G.; Mason,
   H.; Landini, M.
2009SPD....40.1504D    Altcode:
  A new version of the CHIANTI atomic database for astrophysical
  spectroscopy is being prepared for imminent release. This will
  constitute Version 6.0. The main focus of this release is the inclusion
  of ionization cross-sections and rate coefficients from Dere (2007)
  and recombination rate coefficients from the literature, in particular,
  the calculations of Badnell and colleagues. A new set of ionization
  equilibria have been calculated from these rate coefficients. These
  show some significant differences from previous calculations. Atomic
  data for many ions have been revised and new calculations are included
  that enable the calculation of spectra of ions new to the CHIANTI
  database. The radiative loss function has been calculated based on
  the CHIANTI Version 6 database for both coronal and photospheric
  abundances. <P />A paper describing CHIANTI Version 6.0 in detail has
  been accepted for publication in Astronomy and Astrophysics.

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Title: Chiantipy - The Python Interface To Chianti
Authors: Dere, Kenneth P.
2009SPD....40.1505D    Altcode:
  Python is a free, modern, object-oriented programming language that
  is well suited to scientific data analysis. A command line version
  for use within the IPython shell is under development and significant
  progress has already been made. Programmatically, each ion in the
  CHIANTI database is treated as an object, providing a good match to
  the structure of the CHIANTI database. Currently, ChiantiPy is able
  to calculate and plot level populations, spectral line emissivities,
  contribution functions, G(n,T), and line intensity ratios as functions
  of temperature and electron and proton density. A GUI version is
  also planned. <P />The current capabilities of ChiantiPy will be
  demonstrated.

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Title: The plasma filling factor of coronal bright
    points. II. Combined EIS and TRACE results
Authors: Dere, K. P.
2009A&A...497..287D    Altcode:
  Aims: In a previous paper, the volumetric plasma filling factor of
  coronal bright points was determined from spectra obtained with the
  Extreme ultraviolet Imaging Spectrometer (EIS). The analysis of these
  data showed that the median plasma filling factor was 0.015. One
  interpretation of this result was that the small filling factor was
  consistent with a single coronal loop with a width of 1-2´´, somewhat
  below the apparent width. In this paper, higher spatial resolution
  observations with the Transition Region and Corona Explorer (TRACE)
  are used to test this interpretation. <BR />Methods: Rastered spectra
  of regions of the quiet Sun were recorded by the EIS during operations
  with the Hinode satellite. Many of these regions were simultaneously
  observed with TRACE. Calibrated intensities of Fe xii lines were
  obtained and images of the quiet corona were constructed from the EIS
  measurements. Emission measures were determined from the EIS spectra
  and geometrical widths of coronal bright points were obtained from the
  TRACE images. Electron densities were determined from density-sensitive
  line ratios measured with EIS. A comparison of the emission measure
  and bright point widths with the electron densities yielded the plasma
  filling factor. <BR />Results: The median electron density of coronal
  bright points is 3 × 10<SUP>9</SUP> cm<SUP>-3</SUP> at a temperature
  of 1.6 × 10<SUP>6</SUP> K. The volumetric plasma filling factor of
  coronal bright points was found to vary from 3 × 10<SUP>-3</SUP>
  to 0.3 with a median value of 0.04. <BR />Conclusions: The current
  set of EIS and TRACE coronal bright-point observations indicate the
  median value of their plasma filling factor is 0.04. This can be
  interpreted as evidence of a considerable subresolution structure in
  coronal bright points or as the result of a single completely filled
  plasma loop with widths on the order of 0.2-1.5´´ that has not been
  spatially resolved in these measurements.

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Title: The plasma filling factor of coronal bright points. Coronal
    bright points
Authors: Dere, K. P.
2008A&A...491..561D    Altcode:
  Aims: We determine the volumetric plasma filling factor of coronal
  bright points. <BR />Methods: Rastered spectra of the regions of the
  quiet Sun were recorded by the Extreme ultraviolet Imaging Spectrometer
  (EIS) during operations with the Hinode satellite. Calibrated
  intensities of Fe XII lines were obtained and images of the quiet corona
  were constructed. From the imaged spectra, the emission measures and
  geometrical widths of coronal bright points were obtained. Electron
  densities were determined from density-sensitive line ratios. A
  comparison of the emission measure and bright point widths with the
  electron densities yielded the plasma-filling factor. <BR />Results:
  The median electron density of coronal bright points is 4 ×
  10<SUP>9</SUP> cm<SUP>-3</SUP> at a temperature of 1.6×10<SUP>6</SUP>
  K. The volumetric plasma-filling factor of coronal bright points was
  found to vary from 4 × 10<SUP>-5</SUP> to 0.2 with a median value
  of 0.015. <BR />Conclusions: The current set of EIS coronal bright
  point observations indicates that the median value of their plasma
  filling-factor is 0.015. This can be interpreted as evidence of a
  considerable subresolution structure in coronal bright points or as
  the result of a single completely-filled plasma loop with a width on
  the order of 1-2 arcsec that has not been spatially resolved in these
  measurements. <P />Full Table 2 is only available in electronic form
  at http://www.aanda.org

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Title: VizieR Online Data Catalog: Plasma filling factor of coronal
    bright points (Dere+, 2008)
Authors: Dere, K. P.
2008yCat..34910561D    Altcode:
  The data describe the observed and derived properties of a set of corona
  l bright points. The labeling allows the reader to correlate the data
  in Table 2 with their images in Figures 2 and 3. <P />(1 data file).

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Title: The Plasma Filling Factor of Coronal Bright Points
Authors: Dere, K. P.
2008AGUSMSP31D..04D    Altcode:
  Rastered spectra of regions of the quiet Sun were recorded by the
  Extreme ultraviolet Imaging Spectrometer (EIS) during operations with
  the Hinode satellite. Calibrated intensities of Fe XII lines were
  obtained and images of the quiet corona were constructed. From the
  imaged spectra, the emission measures and geometrical widths of coronal
  bright points were obtained. From density-sensitive line ratios,
  electron densities were determined. A comparison of the emission
  measure and bright point widths with the electron densities yielded
  the plasma-filling factor. The median electron density of coronal
  bright points is 2.5 × 109 cm-3 at a temperature of 1.4 × 106K. The
  volumetric plasma filling factor of coronal bright points was found
  to vary from 3 × 10-3 to unity with a median value of 0.02. The small
  filling factors lends support to theories, such as the nanoflare theory
  of Parker, that suggest coronal heating occurs on small spatial scales.

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Title: The Structure and Dynamics of the Quiet Corona from
    Observations with the Extreme ultraviolet Imaging Spectrometer
Authors: Dere, K. P.; Doschek, G. A.; Mariska, J. T.; Harra, L. K.;
   Matsuzaki, K.; Hansteen, V.; Thomas, R. J.
2007AGUFMSH53A1046D    Altcode:
  The goal of the Extreme-ultraviolet Imaging Spectrometer (EIS) on the
  Hinode satellite is to measure such physical parameters as the velocity
  and density of the solar corona in order to provide an observational
  basis to understand how coronal plasmas are heated and accelerated. On
  2007 January 20, EIS performed a raster of a 128 x 512 arc-sec. area
  of a quiet region near Sun center. The observing program recorded
  spectra of He II λ256, formed at 9 × 104 K, and lines of Fe VIII-XV,
  formed at temperatures spanning the range from 5 × 105 through 2 × 106
  K. Maps of intensities, velocities and electron densities derived from
  these observations are presented and discussed. Intensity maps in He II
  λ256 show the chromospheric network. Line intensities of Fe X-XIV show
  small-scale bright points and more extended structures. The intensity
  map of Fe VIII shows a transition between the two temperatures. The
  coronal lines reveal regions of high outflow velocities on the
  order of 100 km s-1 in a compact region and 12 km s-1 in an extended
  region. The presence of these high velocities in the quiet corona
  is an entirely new and unexpected result. Electron densities derived
  from density sensitive line ratios of Fe XII and XIII are typically
  about 3 - 20×108 cm-3. The highest densities are found in bright,
  compact areas. For the first time, explosive events in the quiet sun
  have been observed in the extreme-ultraviolet in He II λ256 profiles
  and have properties similar to those previously reported.

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Title: The Structure and Dynamics of the Quiet Corona from
    Observations with the Extreme Ultraviolet Imaging Spectrometer
    on Hinode
Authors: Dere, Kenneth P.; Doschek, George A.; Mariska, John T.;
   Hansteen, Viggo H.; Harra, Louise K.; Matsuzaki, Keiichi; Thomas,
   Roger J.
2007PASJ...59S.721D    Altcode:
  The goal of the Hinode mission is to provide an observational basis for
  understanding the heating and acceleration of coronal plasmas. On 2007
  January 20, the Extreme ultraviolet Imaging Spectrometer performed
  a raster of a quiet region near Sun center. Maps of intensities,
  velocities, and electron densities derived from these observations are
  presented and discussed. Intensity maps in HeII λ 256, formed at 9
  × 10<SUP>4</SUP> K, show the chromospheric network. Line intensities
  of FeX-XIV, formed at temperatures from 1-2 × 10<SUP>6</SUP> K, show
  small-scale bright points and more extended structures. The intensity
  map of FeVIII shows a transition between the two temperatures. The
  coronal lines reveal regions of high outflow velocities on the order
  of 100kms<SUP>-1</SUP> in a compact region and 12kms<SUP>-1</SUP> in
  an extended region. The presence of such high velocities in the quiet
  corona is an entirely new and unexpected result. Electron densities
  derived from density sensitive line ratios of FeXII and XIII are
  typically 3-20 × 10<SUP>8</SUP>cm<SUP>-3</SUP>. The highest densities
  are found in bright, compact areas. For the first time, explosive
  events in the quiet sun have been observed in the extreme-ultraviolet
  in HeII λ 256 profiles.

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Title: Hot and Cool Loops Composing the Corona of the Quiet Sun
Authors: Matsuzaki, Keiichi; Hara, Hirohisa; Watanabe, Tetsuya; Dere,
   Kenneth P.; Brown, Charles M.; Culhane, Len
2007PASJ...59S.683M    Altcode:
  We performed a raster scan observation of the quiet Sun with the EUV
  Imaging Spectrometer (EIS) aboard Hinode and simultaneously analyzed
  observed emission lines of Fe VIII to XV. From a combined analysis,
  radiance maps from the observed emission lines were deconvolved into
  plasma components at five representative temperatures between 0.40MK and
  2.63MK. While the lowest temperature component shows network structures
  on spatial scales of between 10" and 20", the higher temperature
  components show thread-like patterns on larger scales. A comparison of
  emission measures at the different temperatures suggests that the lowest
  temperature component is mainly composed of bodies of small loops,
  rather than a collection of foot points of the higher temperature
  loops. The difference in morphologies is interpreted as being due to
  different magnetic field configurations, loops within super-granule
  cells and fields extending beyond the boundaries of super-granule cells,
  with distinct peak temperatures following a loop scaling law.

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Title: The Temperature and Density Structure of an Active Region
    Observed with the Extreme-Ultraviolet Imaging Spectrometer on Hinode
Authors: Doschek, George A.; Mariska, John T.; Warren, Harry P.;
   Culhane, Len; Watanabe, Tetsuya; Young, Peter R.; Mason, Helen E.;
   Dere, Kenneth P.
2007PASJ...59S.707D    Altcode:
  The Extreme-Ultraviolet Imaging Spectrometer (EIS) on Hinode
  produces high resolution spectra that can be combined via rasters
  into monochromatic images of solar structures, such as active
  regions. Electron temperature and density maps of the structures can
  be obtained by imaging the structures in different spectral lines with
  ratios sensitive to either temperature or density. Doppler maps and
  ion temperature maps can be made from spectral line wavelengths and
  profiles, respectively. In this paper we discuss coronal temperature
  and density distributions within an active region, illustrating the
  power of EIS for solar plasma diagnostics.

---------------------------------------------------------
Title: EUV Emission Lines and Diagnostics Observed with Hinode/EIS
Authors: Young, Peter R.; Del Zanna, Giulio; Mason, Helen E.; Dere,
   Ken P.; Landi, Enrico; Landini, Massimo; Doschek, George A.; Brown,
   Charles M.; Culhane, Len; Harra, Louise K.; Watanabe, Tetsuya; Hara,
   Hirohisa
2007PASJ...59S.857Y    Altcode: 2007arXiv0706.1857Y
  Quiet Sun and active region spectra from the Hinode/EIS instrument are
  presented, and the strongest lines from different temperature regions
  discussed. A list of emission lines recommended to be included in EIS
  observation studies is presented based on analysis of blending and
  diagnostic potential using the CHIANTI atomic database. In addition
  we identify the most useful density diagnostics from the ions covered
  by EIS.

---------------------------------------------------------
Title: Wavelength Determination for Solar Features Observed by the
    EUV Imaging Spectrometer on Hinode
Authors: Brown, Charles M.; Hara, Hirohisa; Kamio, Suguru; Feldman,
   Uri; Seely, John F.; Doschek, George A.; Mariska, John T.; Korendyke,
   Clarence M.; Lang, James; Dere, Kenneth P.; Culhane, Len; Thomas,
   Roger J.; Davila, Joseph M.
2007PASJ...59S.865B    Altcode:
  A wavelength calibration of solar lines observed by the high
  resolution EUV Imaging Spectrometer (EIS) on the Hinode satellite
  is reported. Spectral features of the quiet sun and of two mildly
  active areas were measured and calibrated. A listing of the stronger
  observed lines with identification of the leading contributor ions
  is presented. 41 lines are reported, with 90% identified. Wavelength
  precisions (2σ) of ±0.0031Å for the EIS short band and ±0.0029Å
  for the EIS long band are obtained. These lines, typical of 1-2
  ×10<SUP>6</SUP> K plasmas, are recommended as standards for the
  establishment of EIS wavelength scales. The temperature of EIS varies
  by about 1D.5 C around the orbit and also with spacecraft pointing. The
  correlation of these temperature changes with wavelength versus pixel
  number scale changes is reported.

---------------------------------------------------------
Title: Application of CHIANTI to Solar-B
Authors: Dere, K.; Landi, E.; Del Zanna, G.; Young, P.; Mason, H.;
   Landini, M.
2007ASPC..369...35D    Altcode:
  CHIANTI (http://wwwsolar.nrl.navy.mil/chianti.html) has been developed
  to support the interpretation of solar and astrophysical spectroscopic
  measurements. The most recent release, version 5.0 (Landi et al. 2005)
  presents an improvement over previous versions by including new
  large scale datasets for Fe ions from Fe XVII to Fe XXIV for X-ray
  emission and improved atomic data for EUV line emission. We will
  demonstrate how this can be applied to the analysis of XRT and EIS
  data, in particular. For example, new excitation rates for Fe XII have
  resolved a long standing problem in the use of Fe XII line ratios as
  accurate density diagnostics. Current work involves improvements to
  ionization and recombination rates which will also be useful in the
  interpretation of Solar-B data

---------------------------------------------------------
Title: VizieR Online Data Catalog: Ionization rate coefficients for
    elements H to Zn (Dere+, 2007)
Authors: Dere, K. P.
2007yCat..34660771D    Altcode:
  This table contains spline fits to scaled ionization rate coefficient
  that will allow the computation of ionization rate coefficients of
  all ions of the elements hydrogen through zinc over a wide range of
  temperatures. <P />This file has been modified from the original to
  correct the values for the calcium-like sequence on September 12,
  2007. <P />(1 data file).

---------------------------------------------------------
Title: The EUV Imaging Spectrometer for Hinode
Authors: Culhane, J. L.; Harra, L. K.; James, A. M.; Al-Janabi, K.;
   Bradley, L. J.; Chaudry, R. A.; Rees, K.; Tandy, J. A.; Thomas, P.;
   Whillock, M. C. R.; Winter, B.; Doschek, G. A.; Korendyke, C. M.;
   Brown, C. M.; Myers, S.; Mariska, J.; Seely, J.; Lang, J.; Kent,
   B. J.; Shaughnessy, B. M.; Young, P. R.; Simnett, G. M.; Castelli,
   C. M.; Mahmoud, S.; Mapson-Menard, H.; Probyn, B. J.; Thomas, R. J.;
   Davila, J.; Dere, K.; Windt, D.; Shea, J.; Hagood, R.; Moye, R.; Hara,
   H.; Watanabe, T.; Matsuzaki, K.; Kosugi, T.; Hansteen, V.; Wikstol, Ø.
2007SoPh..243...19C    Altcode:
  The EUV Imaging Spectrometer (EIS) on Hinode will observe solar corona
  and upper transition region emission lines in the wavelength ranges
  170 - 210 Å and 250 - 290 Å. The line centroid positions and profile
  widths will allow plasma velocities and turbulent or non-thermal line
  broadenings to be measured. We will derive local plasma temperatures and
  densities from the line intensities. The spectra will allow accurate
  determination of differential emission measure and element abundances
  within a variety of corona and transition region structures. These
  powerful spectroscopic diagnostics will allow identification
  and characterization of magnetic reconnection and wave propagation
  processes in the upper solar atmosphere. We will also directly study
  the detailed evolution and heating of coronal loops. The EIS instrument
  incorporates a unique two element, normal incidence design. The optics
  are coated with optimized multilayer coatings. We have selected highly
  efficient, backside-illuminated, thinned CCDs. These design features
  result in an instrument that has significantly greater effective area
  than previous orbiting EUV spectrographs with typical active region
  2 - 5 s exposure times in the brightest lines. EIS can scan a field
  of 6×8.5 arc min with spatial and velocity scales of 1 arc sec and
  25 km s<SUP>−1</SUP> per pixel. The instrument design, its absolute
  calibration, and performance are described in detail in this paper. EIS
  will be used along with the Solar Optical Telescope (SOT) and the X-ray
  Telescope (XRT) for a wide range of studies of the solar atmosphere.

---------------------------------------------------------
Title: Ionization rate coefficients for the elements hydrogen
    through zinc
Authors: Dere, K. P.
2007A&A...466..771D    Altcode:
  Aims:The interpretation of astrophysical spectra depends directly on
  a knowledge of the ionization state of the emitting plasma. This is
  determined, in part, from collisional ionization rate coefficients. The
  most recent assessments of these were performed by Arnaud &amp;
  Rothenflug (1985, A&amp;AS, 60, 425) and Arnaud &amp; Raymond
  (1992, ApJ, 398, 394). Since their work, new laboratory measurements
  of ionization cross sections have become available as well as the
  Flexible Atomic Code (FAC) which enables theoretical calculations of
  these rates. Our goal is to provide a complete set of ionization rate
  coefficients for the elements hydrogen through zinc. <BR />Methods: A
  scaling law, which assists the analysis of ionization cross sections
  and rate coefficients, has been developed following the approach
  of Burgess &amp; Tully (1992, A&amp;A, 254, 436). Essentially all
  available measured cross sections along each isoelectronic sequence
  have been examined and compared to cross sections calculated with
  the Flexible Atomic Code (FAC) and with other calculations. Two
  approaches has been taken to provide a complete set of ionization
  cross sections. In the first, fits to scaled measured ionization cross
  sections, particularly for neutral and singly ionized species, are
  performed. In the second, fits to scaled calculated direct ionization
  and excitation-autoionization cross sections are performed to provide
  the remainder of the set. The fits to the cross sections are then
  integrated over a Maxwellian velocity distribution to derive ionization
  rate coefficients. <BR />Results: A complete set of ground level
  ionization cross sections and rate coefficients has been developed
  through the combination of these two approaches. A tabulation of
  parameter fits to ground level ionization rate coefficients for all
  atoms and ions of the elements of H through Zn is provided. <P />Full
  Table [see full text] is only available in electronic form at the
  CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via
  http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/466/771

---------------------------------------------------------
Title: Transition Region Explosive Events and their Relation to the
    Solar Magnetic Field
Authors: Muglach, Karin; Dere, K.
2007AAS...210.9118M    Altcode: 2007BAAS...39..207M
  Magnetic field restructuring by reconnection is pervasive in solar
  physics. It can potentially provide the energy to heat and accelerate
  the plasma in the solar atmosphere. We will investigate the role
  of small-scale magnetic reconnection in the formation of transition
  region explosive events. These events are defined by strong transient
  enhancements of the wings of spectral lines that form at transition
  region temperatures (between 20 000 - 200 000 K).Using SUMER data
  we are able to identify EEs by their spectral signature. With MDI we
  can continuously map the photospheric magnetic field and search for a
  manifestation of the reconnection in the lower solar atmosphere. We
  have analysed several dozens of explosive events and will show how
  the underlying magnetic field evolves during these events.

---------------------------------------------------------
Title: Two Successive Coronal Mass Ejections Driven by the Kink and
    Drainage Instabilities of an Eruptive Prominence
Authors: Zhou, G. P.; Wang, J. X.; Zhang, J.; Chen, P. F.; Ji, H. S.;
   Dere, K.
2006ApJ...651.1238Z    Altcode:
  We describe a clear case of the initiation of a propagating bright arc
  and a CME on 2002 December 28, which were associated with an eruptive
  prominence. In EIT 304 and 195 Å images, a very long filament showed
  evidence of severe twisting in one of its fragments, which appeared as a
  prominence on December 26; then, the prominence showed the conversion of
  its twist into writhe. Two days later, the prominence displayed a slow
  rising motion for hours. Internal twisting and mass motion took place
  before the rapid acceleration and final eruption. The propagating bright
  arc and the following CME corresponded to the early rising and the
  subsequently eruptive phases of the prominence, respectively. Signatures
  of magnetic reconnection, i.e., a cusp structure and postflare loops
  in EUV wave bands and hard X-ray sources in the corona, were observed
  after the prominence eruption. It appears that the kink instability
  and the mass drainage in the prominence played key roles in triggering
  the initiation of the CME. However, the rather impulsive acceleration
  of the CME resulted from magnetic reconnection beneath the filament.

---------------------------------------------------------
Title: A Statistical Study of Main and Residual Accelerations of
    Coronal Mass Ejections
Authors: Zhang, J.; Dere, K. P.
2006ApJ...649.1100Z    Altcode:
  In this paper we present the results of a statistical study of the
  accelerations of coronal mass ejections (CMEs). A CME usually undergoes
  a multiphased kinematic evolution, with a main acceleration phase
  characterized by a rapid increase of CME velocity in the inner corona,
  followed by a relatively smooth propagation phase characterized by a
  constant speed or a small residual acceleration in the outer corona. We
  study both the main acceleration and the residual acceleration for
  50 CME events based on Large Angle Spectrometric Coronagraph (LASCO)
  observations. We find that the magnitude of the main acceleration
  has a wide distribution, from 2.8 to 4464.0 m s<SUP>-2</SUP>,
  with a median (average) value of 170.1 (330.9 m s<SUP>-2</SUP>),
  and a standard deviation of 644.8 m s<SUP>-2</SUP>, whereas the
  magnitude of the residual acceleration ranges only from -131.0 to
  52.0 m s<SUP>-2</SUP>, with a median (average) value of 3.1 (0.9 m
  s<SUP>-2</SUP>) and a standard deviation of 25.3 m s<SUP>-2</SUP>. The
  duration of the main acceleration is also widely distributed, from 6
  to 1200 minutes, with a median (average) value of 54 (180 minutes) and
  a standard deviation of 286 minutes.We find an intriguing scaling law
  between the acceleration magnitude (A) and the acceleration duration
  (T) over the entire parameter range of almost 3 orders of magnitude,
  which can be expressed as A (m s<SUP>-2</SUP>)=10,000T<SUP>-1</SUP>
  (minutes). The implications of these observational results on the
  issues of CME classification and CME modelings are discussed.

---------------------------------------------------------
Title: The Extreme Ultraviolet Imaging Spectrometer (EIS) on Solar-B
Authors: Doschek, George A.; Brown, C. M.; Korendyke, C. M.; Mariska,
   J. T.; Myers, S. H.; Seely, J. F.; Dere, K. P.; Lang, J.; Culhane,
   J. L.; Watanabe, T.
2006SPD....37.3604D    Altcode: 2006BAAS...38S.260D
  The Extreme Ultraviolet Imaging Spectrometer (EIS) for Solar-B is a
  high throughput state-of-the-art instrument designed to obtain solar
  spectra and images in two wavelength bands centered near 195 and 270
  Angstroms. Traditional spectra can be obtained using narrow slits or
  images of solar structures can be obtained in individual spectral
  lines using wide slots. Essentially, the instrument obtains images
  in wavebands similar to TRACE but in each spectral line within the
  waveband. This removes electron temperature ambiguities inherent in
  broadband imagers and allows dynamic effects to be detected via Doppler
  shifts and densities and other plasma parameters to be measured via
  spectroscopic plasma diagnostics. After a brief description of how
  the instrument works and a comparison with previous instrumentation
  (sensitivity, etc.), the presentation will focus on the science that
  can be accomplished with EIS, presented in the form of sample observing
  sequences. The focus will be on active regions and solar flares with a
  consideration of topics such as temperature and density distributions
  in active region loops and their evolution, dynamical motions in active
  region loops, the reconnection site in solar flares, and temperature
  evolution of multimillion degree flare loops.

---------------------------------------------------------
Title: CMEs driven by an eruptive prominence
Authors: Zhou, G. P.; Wang, J. X.; Zhang, J.; Chen, P. F.; Ji, H. S.;
   Dere, K.
2006IAUS..233..405Z    Altcode:
  A clear case on Dec. 28 2002 is presented. It is about the initiation of
  two successive CMEs, which were related to an eruptive prominence. In
  EIT 304 Å and 195 Å observations, we found a long filament severely
  twisting in a piece of its fragments, which appeared as a prominence on
  Dec. 26. Then, the prominence converted its twist into writhe. Two days
  later, the prominence displayed a slow rising motion for hours. There
  happened internal twisting and mass motion before the prominence rapid
  acceleration and final eruption. Two successive CMEs recorded by LASCO
  C2 coronagraph corresponded to the early rising and the subsequently
  eruptive phases of the prominence, respectively. Evidence of magnetic
  reconnection, i.e., a cusp structure and post-flare loops in EUV
  wavebands, and hard X-ray sources in the corona, were observed after
  the prominence disruption. It appears that the kink instability and the
  mass drainage in the prominence played important roles in triggering two
  CMEs' initiation. We suspected that the rather impulsive acceleration
  of the second CME resulted from magnetic reconnection beneath the
  prominence.

---------------------------------------------------------
Title: CHIANTI-An Atomic Database for Emission Lines. VII. New Data
    for X-Rays and Other Improvements
Authors: Landi, E.; Del Zanna, G.; Young, P. R.; Dere, K. P.; Mason,
   H. E.; Landini, M.
2006ApJS..162..261L    Altcode:
  The CHIANTI atomic database contains atomic energy levels, wavelengths,
  radiative transition probabilities, and collisional excitation data for
  a large number of ions of astrophysical interest. CHIANTI also includes
  a suite of IDL routines to calculate synthetic spectra and carry out
  plasma diagnostics. Version 5 has been released, which includes several
  new features, as well as new data for many ions. The new features in
  CHIANTI are as follows: the inclusion of ionization and recombination
  rates to individual excited levels as a means to populate atomic
  levels; data for Kα and Kβ emission from Fe II to Fe XXIV; new data
  for high-energy configurations in Fe XVII to Fe XXIII; and a complete
  reassessment of level energies and line identifications in the X-ray
  range, multitemperature particle distributions, and photoexcitation
  from any user-defined radiation field. New data for ions already in
  the database, as well as data for ions not present in earlier versions
  of the database, are also included. Version 5 of CHIANTI represents a
  major improvement in the calculation of line emissivities and synthetic
  spectra in the X-ray range and expands and improves theoretical spectra
  calculations in all other wavelength ranges.

---------------------------------------------------------
Title: Observing the Solar atmosphere with the Extreme Ultraviolet
    Imaging Spectrometer on Solar B
Authors: Korendyke, C. M.; Brown, C.; Dere, K.; Doschek, G.; Klimchuk,
   J.; Landi, E.; Mariska, J.; Warren, H.; Lang, J.
2005AGUFMSH41B1124K    Altcode:
  The Extreme Ultraviolet Imaging Spectrometer (EIS) is part of the
  instrument complement on the Solar B satellite, scheduled for launch
  in the summer of 2006. The instrument has been calibrated and is
  presently mounted on the spacecraft. EIS is the most sensitive EUV
  solar spectrometer to be flown. The instrument is the first of a new
  generation of two optical element, solar spectrographs. Preliminary
  results from the laboratory focussing and calibration of the
  instrument will be shown. The instrument wavelength coverage includes
  reasonably bright spectral lines emitted by plasmas from 0.1 to 20 MK
  in temperature. The wavelength range also provides coronal density
  diagnostics. Temperature, density and velocity diagnostics will be
  discussed. An example observing program for exploring active region
  evolution and dynamics will be discussed.

---------------------------------------------------------
Title: Application of CHIANTI to High Resolution Solar Spectra
Authors: Dere, K. P.; Landi, E.
2005AGUFMSH44A..02D    Altcode:
  CHIANTI has been developed to support the interpretation of solar and
  astrophysical spectroscopic measurements. The most recent release,
  version 5.0 (Landi et al., 2005) presents an improvement over previous
  versions by including new large scale datasets for Fe ions from Fe XVII
  to Fe XXIV for X-ray emission and improved atomic data for EUV line
  emission. We will show examples of its use in the analysis of X-ray
  spectra from SMM, ultraviolet spectra from SOHO and the interpretation
  of broadband instruments such as EIT and TRACE. Current work involves
  the analysis of ionization and recombination rates based on recent
  laboratory measurements and calculations with the Flexible Atomic
  Code. The incorporation of ionization and recombination rates into
  CHIANTI will allow us to explore such effects as the effect of finite
  densities on ionization balance and transient and nonthermal ionization
  populations.

---------------------------------------------------------
Title: Coronal and Stellar Mass Ejections, IAU Symposium Proceedings
    of the International Astronomical Union 226,
Authors: Dere, Kenneth; Wang, Jingxiu; Yan, Yihua
2005IAUS..226.....D    Altcode:
  The Sun and other stars eject large clouds of plasma and magnetic
  fields on a continual basis. They are accelerated to high speeds and
  then become capable of producing highly energetic charged particles
  and disrupting the magnetospheres of planets such as the Earth. This
  proceeding reflects recent attempts to understand these processes as
  well as how the magnetic evolution at the base of the corona can cause
  these events, and how stars are capable of rapidly releasing energy
  in the form of mass ejections. Contributions by leading scientists
  make it a valuable astronomical resource.

---------------------------------------------------------
Title: Coronal and Stellar Mass Ejections (IAU S226)
Authors: Dere, Kenneth; Wang, Jingxiu; Yan, Yihua
2005csme.book.....D    Altcode:
  1. Historical introduction; 2. Observation of CMES; 3. CME source
  regions; 4. Theoretical models of CMEs; 5. Comparisons of CME models
  and observations; 6. CMES and energetic particles; 7. ICMEs in the
  heliosphere; 8. CMES and geomagnetic storms; 9. Stellar ejections.

---------------------------------------------------------
Title: Recent developments of the CHIANTI database in the X-ray
    wavelength range
Authors: Landi, E.; Dere, K. P.; Young, P. R.; del Zanna, G.; Mason,
   H. E.; Landini, M.
2005AIPC..774..409L    Altcode:
  CHIANTI is a database of atomic data and transition probabilities that
  allows the calculation of synthetic spectra and plasma diagnostics of
  optically thin plasmas. It is primarily suited for wavelengths shorter
  than 2000 Å but in principle can also be used at longer wavelengths. In
  the present paper we illustrate the latest development of the CHIANTI
  database, that include a huge expansion of the database in the X-ray
  wavelength range, the renewal of several data in the EUV range, and
  the inclusion of ionization and recombination in the level population
  calculation. This enhanced database will constitute the Version 5
  of CHIANTI.

---------------------------------------------------------
Title: The correlation between features in the solar spectrum near
    Mg II and photospheric magnetic fields
Authors: Morrill, J.; Korendyke, C.; Dere, K.
2005AGUSMSP41B..06M    Altcode:
  During the HRTS-9 flight, spectrograms and spectroheliograms where
  obtained of the quiet sun, quiet limb, plage, and sunspots. Previous
  analysis of these observations required the correction of a small set
  of spectra for instrumental distortions and the absolute intensity
  calibration. We have applied these corrections to a larger portion
  of the HRTS-9 observations where the spectrograph slit was rastered
  across a small region of the sun along the solar equator. This set
  of corrected spectrograms has allowed us to generate high spatial and
  spectral resolution spectroheliograms of the observed quiet and active
  portions of the sun. In addition, with use of a magnetogram taken while
  the flight was in progress we have examined the relationship between
  the photospheric magnetic field and both Mg II emission at 280 nm and
  absorption features in the nearby solar spectrum due to both neutral and
  singly ionized species. In this presentation we will present our high
  resolution spectroheliograms as well as results showing the relationship
  between the magnetic field and several specific spectral features.

---------------------------------------------------------
Title: The Extreme Ultraviolet Imaging Spectrometer on Solar-B
Authors: Mariska, J. T.; Brown, C. M.; Doschek, G. A.; Korendyke,
   C. M.; Myers, S. H.; Seely, J. F.; Dere, K. P.; Lang, J.; Culhane,
   J. L.; Watanabe, T.
2005AGUSMSP43A..02M    Altcode:
  The Extreme Ultraviolet Imaging Spectrometer (EIS) is currently under
  development for flight on the Japanese Solar-B satellite. EIS uses a
  multilayer-coated off-axis telescope mirror and a multilayer-coated
  toroidal grating spectrometer to produce stigmatic spectra of solar
  regions isolated by a 1024 arcsec high slit. The instrument produces
  monochromatic images either by rastering the solar image across a
  narrow entrance slit or by using a very wide slit. Half of each optic
  is coated to optimize reflectance at 19.5 nm, and the other half to
  optimize reflectance at 27.0 nm, with each wavelength range imaged
  onto a separate CCD detector. EIS can provide key dynamical and density
  diagnostic information. Combining EIS data with observations from the
  other instruments on Solar-B should provide a detailed picture of solar
  atmospheric processes from the visible surface into the corona. In
  this presentation, we provide details of the instrument's expected
  performance based on calibration of the individual flight optics and
  end-to-end testing at the Rutherford Appleton Laboratory in the UK.

---------------------------------------------------------
Title: Three-dimensional Structure of Coronal Mass Ejections from
    LASCO Polarization Measurements
Authors: Dere, Kenneth P.; Wang, Dennis; Howard, Russell
2005ApJ...620L.119D    Altcode:
  The three-dimensional structure of a coronal mass ejection (CME)
  is essential information for understanding the process by which they
  are ejected from the Sun. Coronagraphic measurements readily provide
  information on the structure of CMEs in the plane of the sky. It has
  been known for some time that polarization measurements can provide
  information on the position of coronal plasmas out of the plane of
  the sky. Recently, T. G. Moran &amp; J. M. Davila have shown that
  polarimetric measurements with the Large Angle and Spectrometric
  Coronagraph (LASCO) can be used to determine the three-dimensional
  structure of a CME with considerable definition. We have examined a
  series of high-cadence (1 hr) LASCO polarization measurements obtained
  during 2002 and discuss the analysis of two particularly well observed
  events. One event indicates that the CME structure is that of a rising
  arcade of loops, while the other appears to consist of a flux-rope
  type of structure. Because we have examined a large, relatively high
  cadence set of LASCO observations, we have been able to select events
  that provide significantly greater definition of CME structure than
  previously possible.

---------------------------------------------------------
Title: The Three Dimensional Structure of CMEs from LASCO Polarization
    Measurements
Authors: Dere, Kenneth; Wang, Dennis
2005IAUS..226..114D    Altcode:
  The degree of polarization of Compton-scattered photospheric light
  observed in a coronagraph is dependent on the distance of the scattering
  electrons from the plane of the sky. Measurements of the polarization
  of light scattered by CME structures have been observed by LASCO C2. We
  have reduced and analyzed a month long sequence of such measurements
  which were taken at a cadence of 1 hour. The CME brightness has been
  distributed throughout a 3 dimensional cube and visualized at a variety
  of angles. Several CMEs are found to have considerable fine-structure
  consistent with expanding loop arcades. The analysis is subject to a
  variety of assumptions such as a lack of knowledge of whether a source
  is before or behind the plane of the sky. Nevertheless, the results
  obtained to date are intriguing.

---------------------------------------------------------
Title: The CHIANTI database
Authors: Landi, E.; Dere, K. P.; Young, P. R.; Landini, M.; Mason,
   H. E.; Del Zanna, G.
2005HiA....13..653L    Altcode:
  CHIANTI is a database of atomic data and transition rates necessary for
  calculating synthetic spectra and carrying out plasma diagnostics of
  astrophysical sources in the X-ray EUV and UV wavelength ranges. CHIANTI
  includes both line and continuum emission from all astrophysically
  abundant elements in the universe. All data are taken from refereed
  literature and are critically assessed. CHIANTI also includes a suite
  of IDL programs that allow spectroscopic analysis to be carried
  out. CHIANTI data and software are freely distributed over the
  internet. <P />In the present talk I will describe the contents of
  the CHIANTI database its current status and the areas where CHIANTI
  is being developed and I will also present a comparison of CHIANTI
  predictions with the X-ray emission from astrophysical sources.

---------------------------------------------------------
Title: The Evolution of Photospheric Source Regions of CMEs
Authors: Muglach, K.; Dere, K.
2005IAUS..226..179M    Altcode:
  In this presentation we determine the source regions of CMEs that
  were observed with SoHO/LASCO during times of solar activity maximum
  (Feb./Mar. 2000) and during the declining phase of the solar cycle
  (Nov./Dec. 2002). The CMEs were traced back onto the disk and EIT
  EUV images were used for identifying the sources. With the help of
  MDI synoptic magnetograms we follow the evolution of the photospheric
  magnetic flux about 24h before and 12h after the event. We find that
  about 87% of the identified CME source regions show small-scale
  flux changes before the event, usually flux emergence and/or flux
  disappearance. In 13% of the cases we find no signature of photospheric
  flux changes.

---------------------------------------------------------
Title: The 3D structure of CMEs from LASCO polarization measurements
Authors: Dere, K. P.; Wang, D.; Howard, R.
2004AGUFMSH22A..03D    Altcode:
  The polarization of Compton scattered light from a coronal plasma
  is a function of the distance of that plasma from the plane of the
  sky. From an image of the polarization of the corona it is possible
  to construct a 3D cube of intensity which can be visualized at any
  angle to study it's three dimensional distribution. For a one month
  period during July and August 2002, the LASCO C2 coronagraph performed
  polarization measurements with a one hour cadence. During this period,
  several CMEs were well observed. Two CMEs give the appearance of an
  ejecting loop arcade. Another CME is not as easily described but may
  indicate the presence of a flux tube. There are two main ambiguities in
  the analysis. First, a given polarization can be produced by scattering
  from in front of or behind the plane of the sky. This ambiguity can
  be overcome by selecting CMEs that are completely out of the plane of
  the sky. Second, in reconstructing the 3D distribution of intensity,
  it is assumed that the intensity can be visualized as coming from a
  single point in 3D space. The filamentary structures commonly seen in
  the 3D visualizations suggest that this is not a significant problem.

---------------------------------------------------------
Title: Solar UV Spectral Radiance from SKYLAB
Authors: Morrill, J.; Korendyke, C.; Dere, K.
2004AGUFMSH53A0305M    Altcode:
  As part of an ongoing NASA-LWS sponsored research program, solar UV
  spectral radiance has been determined for the quiet sun at a variety
  of center-to-limb positions observed by the SO82B UV spectrograph
  on SKYLAB. This has been done using a high quality flatbed scanner
  to digitize the SKYLAB film data. The goal of the present program
  is to develop a spectral irradiance model that utilizes the full
  resolution of the SKYLAB spectra (~ 0.010 nm at 300 nm). The model
  requires detailed knowledge of the center-to-limb variation (CLV) at
  full resolution over the 200 - 400nm wavelength range. This information
  is also required to determine the absolute intensity calibration which
  uses full-disk irradiance measurements from UARS (SOLSTICE and SUSIM)
  in addition to the CLV. This calibration is then used to derive the disk
  center radiance. In addition to the quiet sun, spectra of sunspots and
  active regions are also being digitized and an attempt is underway to
  derive the CLV for these surface morphologies as well. Further, spectra
  at shorter wavelength (~120 - 200nm) are being examined in order to
  extend the wavelength coverage of these radiance and CLV results. In
  this presentation we will present the details of the analysis methods
  and results for the quiet sun. Ongoing work on sunspots and active
  regions will be presented as will results involving work on shorter
  wavelength spectra.

---------------------------------------------------------
Title: The Evolution of Photospheric Source Regions of CMEs
Authors: Muglach, K.; Dere, K.
2004AAS...204.3808M    Altcode: 2004BAAS...36..713M
  In this presentation we determine the source regions of CMEs that
  were observed with SOHO/LASCO during times of solar activity maximum
  (Feb./Mar. 2000) and during the declining phase of the solar cycle
  (Nov./Dec. 2002). The CMEs were traced back onto the disk and EIT EUV
  images were used for identifying the sources. With the help of MDI
  synoptic and high cadence magnetograms we follow the evolution of the
  photospheric magnetic flux about 12 h before and after the event. We
  find that 80% of the identified CMEs (29 out of a total of 36 events)
  show small--scale flux changes before the event, usually flux emergence
  or flux disappearance. In 20% of the cases we find no signature of
  photospheric flux changes.

---------------------------------------------------------
Title: A Comparison of the Mg II Index Derived from Estimated and
    Observed Solar Spectra
Authors: Morrill, J.; Korendyke, C.; Dere, K.
2004AAS...204.7207M    Altcode: 2004BAAS...36..799M
  We have estimated values of the Mg II index using a model of solar
  spectral irradiance developed at the Naval Research Laboratory. This
  model uses Ca II K images and spatially resolved sun spot, quiet sun,
  and active sun spectra measured by the HRTS-9 rocket to generate the
  estimated spectra. These spectra are compared to observed spectra such
  as the UARS-SUSIM and UARS-SOLSTICE data sets. In order to further
  compare the observed and estimated spectra, a Mg II index is derived
  from these two sets of spectra. In this presentation we will review
  the details of the model, discuss the methods of deriving the Mg II
  index, and compare the Mg II variability resulting from the observed
  and estimated spectra.

---------------------------------------------------------
Title: Recent development of the CHIANTI database in the X-ray
    wavelength range
Authors: Landi, E.; Dere, K. P.; Mason, H. E.; Del Zanna, G.; Landini,
   M.; Young, P. R.
2004AAS...204.7310L    Altcode: 2004BAAS...36R.801L
  CHIANTI consists of a database of critically assessed atomic data
  and transition rates to calculate line and continuum emission
  from astrophysical plasmas. <P />During the last year the CHIANTI
  database has been substantially expanded in the X-ray wavelength
  region by including a large number of new configurations and lines,
  and by including ionization and recombination processes in the level
  population calculations. <P />We will describe these improvements,
  the data we used, and illustrate examples of 1) their effects on
  predicted emissivities and on plasma diagnostics 2) applications to
  the study of flares in solar active regions

---------------------------------------------------------
Title: A Study of the Kinematic Evolution of Coronal Mass Ejections
Authors: Zhang, J.; Dere, K. P.; Howard, R. A.; Vourlidas, A.
2004ApJ...604..420Z    Altcode:
  We report the kinematic properties of a set of three coronal
  mass ejections (CMEs) observed with the LASCO (Large Angle and
  Spectrometric Coronagraph) on the Solar and Heliospheric Observatory
  (SOHO) spacecraft, which showed characteristics of impulsive,
  intermediate, and gradual acceleration, respectively. The first CME
  had a 30 minute long fast acceleration phase during which the average
  acceleration was about 308 m s<SUP>-2</SUP> this acceleration took
  place over a distance of about 3.3 R<SUB>solar</SUB> (from 1.3 to
  4.6 R<SUB>solar</SUB>, height measured from disk center). The CME
  characterized by intermediate acceleration had a long acceleration
  phase of about 160 minutes during which the average acceleration was
  about 131 m s<SUP>-2</SUP> the CME traveled a distance of at least
  4.3 R<SUB>solar</SUB>, reaching a height of 7.0 R<SUB>solar</SUB> at
  the end of the acceleration phase. The CME characterized by gradual
  acceleration had no fast acceleration phase. Instead, it displayed a
  persistent weak acceleration lasting more than 24 hr with an average
  acceleration of only 4.0 m s<SUP>-2</SUP> throughout the LASCO field
  of view (from 1.1 to 30 R<SUB>solar</SUB>). This study demonstrates
  that the final velocity of a CME is determined by a combination of
  acceleration magnitude and acceleration duration, both of which can
  vary significantly from event to event. The first two CME events were
  associated with soft X-ray flares. We found that in the acceleration
  phase there was close temporal correlation both between the CME velocity
  and the soft X-ray flux of the flare and between the CME acceleration
  and derivative of the X-ray flux. These correlations indicate that
  the CME large-scale acceleration and the flare particle acceleration
  are strongly coupled physical phenomena occurring in the corona.

---------------------------------------------------------
Title: Performance of multilayer-coated gratings for the
    extreme-ultraviolet imaging spectrometer (EIS) for the Solar-B mission
Authors: Seely, John F.; Windt, David L.; Donguy, Soizik; Brown,
   Charles; Holland, Glenn; Hunter, William R.; Kowalski, Michael
   P.; Kjornrattanawanich, Benjawan; Doschek, George; Mariska, John;
   Korendyke, Clarence; Dere, Ken
2004SPIE.5168...12S    Altcode:
  The measured efficiencies of two flight gratings and the reflectances
  of two flight mirrors developed for the Extreme-Ultraviolet Imaging
  Spectrometer (EIS) for the Japanese Solar-B mission are presented. Each
  optic has two sectors with Mo/Si multilayers that refelct the 17 -
  21 nm and 25 - 29 nm wavebands at normal incidence. The efficiencies
  that were measured using monochromatic synchrotron radiation are in
  good agreement with the calculated efficiencies.

---------------------------------------------------------
Title: CHIANTI -- An Atomic Database for UV and X-ray Cool star
    spectroscopy
Authors: Young, P. R.; Landi, E.; Bromage, G. E.; del Zanna, G.;
   Dere, K. P.; Landini, M.; Mason, H. E.
2003csss...12.1119Y    Altcode:
  The CHIANTI atomic database was first released in 1996 and has since
  become the standard resource for the interpretation of UV spectra
  from the transition regions and coronae of the Sun and other cool
  stars. We describe the contents of the most recent release (v.3)
  and some of the uses that have been found for the database.

---------------------------------------------------------
Title: Expected Performance of the Extreme Ultraviolet Imaging
    Spectrometer on Solar-B
Authors: Mariska, J. T.; Brown, C. M.; Dere, K. P.; Doschek, G. A.;
   Korendyke, C. M.; Myers, S. H.; Seely, J. F.; Culhane, J. L.;
   Watanabe, T.
2003SPD....34.2006M    Altcode: 2003BAAS...35..845M
  The Extreme Ultraviolet Imaging Spectrometer (EIS) is currently under
  development for flight on the Japanese Solar-B satellite. EIS uses a
  multilayer-coated off-axis telescope mirror and a multilayer-coated
  toroidal grating spectrometer to produce stigmatic spectra of solar
  regions isolated by a 1024 arcsec high slit. The instrument produces
  monochromatic images either by rastering the solar image across a
  narrow entrance slit or by using a very wide slit. Half of each optic
  is coated to optimize reflectance at 19.5 nm, and the other half to
  optimize reflectance at 27.0 nm, with each wavelength range imaged
  onto a separate CCD detector. <P />In this presentation we provide an
  update on the EIS hardware development and show details of the expected
  performance of the instrument in solar quiet regions, active regions,
  and flares.

---------------------------------------------------------
Title: Normal-incidence EXtreme-Ultraviolet imaging Spectrometer
    - NEXUS
Authors: Dere, K. P.
2003SPD....34.2405D    Altcode: 2003BAAS...35..853D
  NEXUS is the result of a breakthrough optical design that incorporates
  new technologies to achieve high optical throughput at high spatial
  (1 arcsec) and spectral (1-2 km s<SUP>-1</SUP>) resolution over
  a wide field of view in an optimal extreme-ultraviolet spectral
  band. This achievement was made possible primarily by two technical
  developments. First, a coating of boron-carbide deposited onto a layer
  of iridium provided a greatly enhanced reflectivity at EUV wavelengths
  that would enable NEXUS to observe the Sun over a wide temperature
  range at high cadence. The reflectivity of these coatings have been
  measured and demonstrated in the laboratory. <P />The second key
  development was the use of a variable-line-spaced toroidal grating
  spectrometer. The spectrometer design allowed the Sun to be imaged
  at high spatial and spectral resolution along a 1 solar radius-long
  slit and over a wavelength range from 450 to 800 Å, nearly an entire
  spectral order. Because the spectrograph provided a magnification of
  about a factor of 6, only 2 optical elements are required to achieved
  the desired imaging performance. Throughput was enhanced by the use
  of only 2 reflections. The could all be accomodated within a total
  instrument length of 1.5m. <P />We would like to acknowledge support
  from ONR

---------------------------------------------------------
Title: Association between CME/Flare Events and Enhanced Oxygen
    Charge States
Authors: Reinard, A. A.; Dere, K.; Howard, R.
2003SPD....34.0608R    Altcode: 2003BAAS...35..818R
  We present results from a study of coronal mass ejection (CME) data
  obtained both optically (from SOHO/LASCO and SOHO/EIT) and in situ
  (from ACE). Phenomena associated with optical CMEs, such as flares
  and radio bursts, are compared with heliospheric CME signatures,
  such as enhanced charge states and elevated helium densities, to
  determine if there is any correspondence between them. A casual
  relationship has been seen between CMEs with large flares and ICMEs
  with enhanced oxygen charge state ratios. This relationship will be
  further investigated. An understanding of how CME observations at the
  Sun relate to CME observations in the heliosphere will increase our
  understanding of CME dynamics and may provide insight into CME origins.

---------------------------------------------------------
Title: High Resolution Limb Darkening Function Near 2800 /AA/
    Measured by HRTS
Authors: Morrill, J. S.; Dere, K. P.; Korendyke, C. M.
2003SPD....34.1909M    Altcode: 2003BAAS...35..843M
  We are currently developing an empirical model of solar spectral
  irradiance varaibility. This model will combine ground based
  observations of the areas and locations of plage and sunspots with
  measured wavelength dependent contrast factors in order to estimate
  the solar spectrum. One important component of this model is the
  wavelength dependent limb darking function that must be determined
  at high resolution. Using quiet sun spectra near Mg II at about 2800
  /AA/ measured by the NRL HRTS instrument, we have recently determined
  this function for the quiet sun. This function shows many features
  similar to those seen in the active region contast that we have
  reported earlier. In this presentation we will discuss the method of
  determining the limb darkening function in the 2765 -2885 /AA/ region
  and it's impact on the irradiance model.

---------------------------------------------------------
Title: CHIANTI-An Atomic Database for Emission Lines. VI. Proton
    Rates and Other Improvements
Authors: Young, P. R.; Del Zanna, G.; Landi, E.; Dere, K. P.; Mason,
   H. E.; Landini, M.
2003ApJS..144..135Y    Altcode: 2002astro.ph..9493Y
  The CHIANTI atomic database contains atomic energy levels, wavelengths,
  radiative transition probabilities, and electron excitation data for
  a large number of ions of astrophysical interest. Version 4 has been
  released, and proton excitation data are now included, principally
  for ground configuration levels that are close in energy. The fitting
  procedure for excitation data, both electrons and protons, has been
  extended to allow nine-point spline fits in addition to the previous
  five-point spline fits. This allows higher quality fits to data from
  close-coupling calculations where resonances can lead to significant
  structure in the Maxwellian-averaged collision strengths. The effects
  of photoexcitation and stimulated emission by a blackbody radiation
  field in a spherical geometry on the level balance equations of
  the CHIANTI ions can now be studied following modifications to the
  CHIANTI software. With the addition of H I, He I, and N I, the first
  neutral species have been added to CHIANTI. Many updates to existing
  ion data sets are described, while several new ions have been added
  to the database, including Ar IV, Fe VI, and Ni XXI. The two-photon
  continuum is now included in the spectral synthesis routines, and a
  new code for calculating the relativistic free-free continuum has been
  added. The treatment of the free-bound continuum has also been updated.

---------------------------------------------------------
Title: Identification of Solar Sources of Major Geomagnetic Storms
    between 1996 and 2000
Authors: Zhang, J.; Dere, K. P.; Howard, R. A.; Bothmer, V.
2003ApJ...582..520Z    Altcode:
  This paper presents identification of solar coronal mass ejection (CME)
  sources for 27 major geomagnetic storms (defined by disturbance storm
  timeindex&lt;=-100 nT) occurring between 1996 and 2000. Observations of
  CMEs and their solar surface origins are obtained from the Large Angle
  and Spectrometric Coronagraph (LASCO) and the EUV Imaging Telescope
  (EIT) instruments on the SOHO spacecraft. Our identification has
  two steps. The first step is to select candidate front-side halo
  (FSH) CMEs using a fixed 120 hr time window. The second step is
  to use solar wind data to provide further constraints, e.g., an
  adaptive time window defined based on the solar wind speed of the
  corresponding interplanetary CMEs. We finally find that 16 of the
  27 (59%) major geomagnetic storms are identified with unique FSH
  CMEs. Six of the 27 events (22%) are associated with multiple FSH
  CMEs. These six events show complex solar wind flows and complex
  geomagnetic activity, which are probably the result of multiple halo
  CMEs interacting in interplanetary space. A complex event occurs when
  multiple FSH CMEs are produced within a short period. Four of the 27
  (15%) events are associated with partial-halo gradual CMEs emerging
  from the east limb. The surface origin of these events is not known
  because of a lack of any EIT signature. We believe that they are
  longitudinally extended CMEs having a component moving along the
  Sun-Earth connection line. One of the 27 major geomagnetic storms is
  caused by a corotating interaction region. We find an asymmetry in
  the longitudinal distribution of solar source region for the CMEs
  responsible for major geomagnetic storms. They are more likely
  to originate from the western hemisphere than from the eastern
  hemisphere. In terms of latitude, most geoeffective CMEs originate
  within a latitude strip of +/-30°. The average transit time for a
  solar CME to arrive at the near-Earth space is found to be 64 hr,
  while it takes 78 hr on average to reach the peak of the geomagnetic
  storm. There is a correlation between CME transit time from the Sun
  to the near-Earth space (T, in hours) and the CME initial velocity
  (V, in unit of kilometers per second) at the Sun, which can be simply
  described as T=96-(V/21). We also find that while these geoeffective
  CMEs are either full-halo CMEs (67%) or partial-halo CMEs (30%),
  there is no preference for them to be fast CMEs or to be associated
  with major flares and erupting filaments.

---------------------------------------------------------
Title: In Situ and Heliospheric CME Signature Relations
Authors: Reinard, Alysha; Dere, K.; Howard, R.; Zurbuchen, T.
2003IAUJD...7E..31R    Altcode:
  We present results from a study of coronal mass ejection (CME) data
  obtained both optically (from SOHO/LASCO and SOHO/EIT) and in situ (from
  ACE). Phenomena associated with optical CMEs such as flares and radio
  bursts are compared with heliospheric CME signatures such as enhanced
  charge states and elevated helium densities to determine if there is
  any correspondence between them. A casual relationship has been seen
  between CMEs with large flares and ICMEs with enhanced oxygen charge
  state ratios. This relationship will be further investigated. An
  understanding of how CME observations at the Sun relate to CME
  observations in the heliosphere will increase our understanding of
  CME dynamics and may provide insight into CME origins.

---------------------------------------------------------
Title: Chianti: Inclusion of Ionization and Recombination Rates
Authors: Dere, Kenneth P.
2003IAUJD..17E..17D    Altcode:
  The spectrum produced by an astrophysical plasma is directly dependent
  on the ionization state of the plasma. In order to understand
  the ionization balance it is necessary to know the ionization and
  recombination rates of the various ions whether the plasma is in a
  steady-state ionization state or a transient ionization state. <P
  />New and improved measurements and calculations of ionization and
  recombination rate continue to become available. We have collected the
  various measurements and calculations for inclusion into the CHIANTI
  database. We have developed a scaling law for the ionization rates
  similar to that of Burgess and Tully (1992) for electron excitation
  rates. We will discuss our progress the adjustments needed for the
  new rates and the need for more measurements and calculations.

---------------------------------------------------------
Title: CHIANTI - An Atomic Database for XUV Emission Lines
Authors: Landi, Enrico; Dere, Ken P.; Landini, Massimo; Young, Peter
   R.; Mason, Helen E.; del Zanna, Giulio
2003IAUJD..17E..10L    Altcode:
  CHIANTI is a database of atomic data and transition rates necessary for
  calculating synthetic spectra and carrying out plasma diagnostics of
  astrophysical sources in the X-ray EUV and UV wavelength ranges. CHIANTI
  includes both line and continuum emission from all astrophysically
  abundant elements in the universe. All data are taken from refereed
  literature and are critically assessed. CHIANTI also includes a suite
  of IDL programs that allow spectroscopic analysis to be carried
  out. CHIANTI data and software are freely distributed over the
  internet. <P />In the present talk I will describe the contents of
  the CHIANTI database its current status and the areas where CHIANTI
  is being developed and I will also present a comparison of CHIANTI
  predictions with the X-ray emission from astrophysical sources.

---------------------------------------------------------
Title: A Comparison between Coronal Emission Lines from an Isothermal
    Spectrum Observed with the Coronal Diagnostic Spectrometer and
    CHIANTI Emissivities
Authors: Landi, E.; Feldman, U.; Dere, K. P.
2002ApJ...574..495L    Altcode:
  The present paper compares off-disk spectral observations of the
  solar corona in the ranges 307-379 and 513-633 Å with theoretical
  emissivities calculated using the CHIANTI database. The observed spectra
  were recorded by the Coronal Diagnostic Spectrometer instrument on
  board the Solar and Heliospheric Observatory using the normal-incidence
  portion of the instrument. Using line-ratio techniques, we first measure
  the electron temperature and density in the emitting region, verifying
  that it is nearly isothermal. Next, we use an emission-measure analysis
  to compare measured spectral line intensities with predictions from the
  CHIANTI database. This comparison allows us to assess the quality of
  the CHIANTI data for the brightest coronal lines in the 307-379 and
  513-633 Å spectral ranges. As a result, we are able to (1) select
  lines and ions for which the agreement between theory and observation
  is good, (2) identify a few lines that are blended, and (3) stress
  inconsistencies between a few lines and theory, thus showing where
  improvements to atomic data and transition probabilities are necessary.

---------------------------------------------------------
Title: Identifying Solar Sources of Major Geomagnetic Storms
Authors: Zhang, J.; Dere, K. P.; Howard, R. A.
2002AAS...200.2805Z    Altcode: 2002BAAS...34..680Z
  We identify solar coronal mass ejection (CME) sources for 27 (out
  of 38) major geomagnetic storm events occurred between 1996 and 2000
  based on complete solar and interplanetary observations from SOHO, ACE
  and WIND spacecrafts. Our search begins with selecting all front-side
  halo CMEs (FSH CMEs) based on a fixed transition window of 30--120
  hours before the Dst peak time. Valid transition window is reduced
  by using solar wind speed of corresponding ICME (Interplanetary CME)
  for solar CMEs that are ejected at a speed higher than background
  solar wind. We find that 15 of the 27 (60%) major geomagnetic storms
  can be uniquely identified with a single FSH CME. However, 6 of the
  27 events (20%) have multiple FSH CME sources. The complex solar wind
  flow of these events indicate interaction of CMEs in their path toward
  the Earth. The left 6 events (20%) have no FSH CME in the transition
  window. It appears that 4 out of the 6 events are caused by partial
  halo gradual CMEs originated from east limb, which are believed to
  be longitudinal extended gradual CMEs with intrinsic wide-angle. One
  event is caused by an impulsive CME from west limb, and another event
  is caused by corotating interaction region (CIR) associated with a low
  latitude coronal hole. The average transition time from the Sun to the
  Earth is 64 hours while it is 78 hours to reach peak of geomagnetic
  storms. There is a coarse correlation between CME speed (V in km/s)
  and transition time (to ICME, T in hr.), simply as T=96-V/21. We
  find that geo-effective CMEs are more likely originated from western
  hemisphere than from eastern hemisphere. Almost all geo-effective CMEs
  from western hemisphere are full halo CMEs, while most geo-effective
  CMEs from eastern hemisphere are partial halo CMEs.

---------------------------------------------------------
Title: CHIANTI-An Atomic Database for Emission Lines. V. Comparison
    with an Isothermal Spectrum Observed with SUMER
Authors: Landi, E.; Feldman, U.; Dere, K. P.
2002ApJS..139..281L    Altcode:
  CHIANTI is a database consisting of critically evaluated atomic data and
  transition probabilities necessary to analyze spectral observations
  of optically thin plasmas. Previous papers described the content
  of the database and compared it to a solar active region spectrum
  between 170 and 450 Å. The aim of the present paper is to compare
  CHIANTI predictions to off-disk spectral observations of the solar
  corona between 500 and 1500 Å. The observed spectra were recorded by
  the SUMER instrument on board the Solar and Heliospheric Observatory
  using the full spectral range allowed by the instrument. Earlier works
  have demonstrated that the particular emitting plasma is isothermal
  at a temperature of 1.35×10<SUP>6</SUP> K, making it ideal for the
  assessment of the accuracy of the CHIANTI database. This assessment of
  the CHIANTI database allowed us (1) to select lines and ions for which
  the agreement between theory and observation is good, (2) to identify
  several lines which are blended, and (3) to stress inconsistencies
  between a few lines and theory, thus showing where improvements to
  atomic data and transition probabilities are necessary.

---------------------------------------------------------
Title: Sun earth connection coronal and heliospheric investigation
    (SECCHI)
Authors: Howard, R. A.; Moses, J. D.; Socker, D. G.; Dere, K. P.;
   Cook, J. W.; Secchi Consortium
2002AdSpR..29.2017H    Altcode:
  The Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI)
  on the NASA Solar Terrestrial Relations Observatory ( STEREO) mission
  is a suite of remote sensing instruments consisting of an extreme
  ultraviolet imager, two white light coronagraphs, and a heliospheric
  imager. Two spacecraft with identical instrumentation will obtain
  simultaneous observations from viewpoints of increasing separation
  in the ecliptic plane. In support of the STEREO mission objectives,
  SECCHI will observe coronal mass ejections from their birth at the Sun,
  through the outer corona, to their impact at Earth. The SECCHI program
  includes a coordinated effort to develope magneto-hydrodynamic models
  and visualization tools to interpret the images that will be obtained
  from the two spacecraft viewpoints. The resulting three-dimensional
  analysis of CMEs will help to resolve some of the fundamental
  outstanding questions in solar physics.

---------------------------------------------------------
Title: The CHIANTI Atomic Database and Instrument Calibration:
    a Symbiosis
Authors: Mason, H. E.; Del Zanna, G.; Dere, K. P.; Landi, E.; Landini,
   M.; Young, P. R.
2002ISSIR...2..271M    Altcode: 2002ESASR...2..271M; 2002rcs..conf..271M
  The CHIANTI atomic database comprises a comprehensive, accurate and
  up-to-date database of atomic parameters, necessary for emission-line
  spectroscopy. The suite of user-friendly software allows plasma
  diagnostics to be carried out. Since its release in 1996, CHIANTI has
  become a standard resource for the analysis of solar spectra. Accurate
  atomic data can provide the foundation for in-flight instrument
  calibrations. Conversely, an accurate instrument calibration can provide
  a check on atomic parameters. The internal consistency of spectral-line
  intensities can be used to highlight specific anomalies. In this paper,
  we illustrate how CHIANTI has been used to validate the calibration of
  solar EUV instruments: SOHO-CDS, -SUMER, -EIT and SERTS. In addition,
  we show how anomalous spectral-line intensities indicate the need for
  more accurate atomic calculations.

---------------------------------------------------------
Title: Relationship Between Coronal Mass Ejections and Flares
Authors: Zhang, J.; Dere, K.; Howard, R. A.
2001AGUFMSH31C..05Z    Altcode:
  We present the results of our observational study about the relationship
  between CMEs (Coronal Mass Ejections) and flares. We make use of
  CME events well observed by the LASCO instrument (Large Angle and
  Spectrometric Coronagraph), which are suitable for studying their
  detailed kinematic evolution throughout the lower corona (1.1--3
  Rsun, the LASCO C1 field of view) and the upper corona (2--30 Rsun,
  the LASCO C2/C3 field of view). We make height-time and velocity-time
  plots for these events, giving special attention to the height range
  of the lower corona where CME acceleration takes place. We find that
  the evolution of impulsive CMEs can be divided into three phases:
  initiation phase characterized by slow ascension (less than 80 km/s),
  impulsive acceleration phase, and subsequent propagation phase. The
  initiation phase starts earlier than the onset time of the associated
  flare. However, the onset time of the impulsive acceleration phase
  coincides with the onset time of the flare, and the acceleration
  period of the impulsive acceleration phase coincides with the rise
  phase of the flare. Gradual CMEs, which are not associated with flares,
  do not show an impulsive acceleration phase. On the other hand, there
  exists another class of CMEs, which we call explosive CMEs. Explosive
  CMEs are accelerated extremely fast to reach a great velocity;
  the acceleration takes place very low in the corona (less than 0.5
  Rsun above the surface). They do not show an initiation phase and
  are associated with major flares. The Nov. 6, 1997 CME/flare event,
  which is a great particle event, is a typical explosive one and will
  be discussed in detail in the presentation

---------------------------------------------------------
Title: Solar Irradiance Variability Modeled Near Mg II Using Plage
    and Sunspot Contrast Factors Measured by HRTS
Authors: Morrill, J. S.; Dere, K. P.; Korendyke, C. M.; Floyd, L. E.
2001AGUFMSH11C0733M    Altcode:
  Empirical models of solar spectral irradiance varaibility combine areas
  and locations of plage and sunspots with wavelength dependent contrast
  factors in order to estimate the solar spectrum. At UV wavelengths,
  these models have relied on estimated or calculated contrast factors
  that are often at low resolution. Using quiet sun, plage, and sunspot
  spectra near Mg II at ~ 2800Å measured by the NRL HRTS instrument,
  we have recently determined the wavelength dependent contrast factors
  for plage and sunspots. In this presentation we will discuss the use of
  measured contrast factors in a spectral irradiance model of the 2765 -
  2885Å region and the preliminary comparisons of model results with
  SUSIM observations. These comparisons will examine spectral irradiance
  variations on solar rotational and solar cycle time scales.

---------------------------------------------------------
Title: Source Regions of Coronal Mass Ejections
Authors: Subramanian, Prasad; Dere, K. P.
2001ApJ...561..372S    Altcode: 2001astro.ph..7138S
  Observations of the solar corona with the Large Angle and
  Spectrometric Coronagraph Experiment (LASCO) and EUV Imaging
  Telescope (EIT) instruments on the Solar and Heliospheric Observatory
  (SOHO) provide an unprecedented opportunity to study coronal mass
  ejections (CMEs) from their initiation through their evolution out
  to 30 R<SUB>solar</SUB>. The objective of this study is to gain an
  understanding of the source regions from which the CMEs emanate. To
  this end, we have developed a list of 32 CMEs whose source regions
  are located on the solar disk and are well observed in EIT 195 Å data
  during the period from solar minimum in 1996 January through the rising
  part of the cycle in 1998 May. We compare the EIT source regions with
  photospheric magnetograms from the Michelson Doppler Imager (MDI)
  instrument on SOHO and the National Solar Observatory at Kitt Peak
  and also with Hα data from various sources. The overall results of
  our study show that 41% of the CME-related transients observed are
  associated with active regions and have no prominence eruptions, 44%
  are associated with eruptions of prominences embedded in active regions,
  and 15% are associated with eruptions of prominences outside active
  regions. Those CMEs that do not involve prominence eruptions originate
  in active regions both with and without prominences. We describe six
  especially well observed events. These case studies suggest that active
  region CMEs (without eruptive prominences) are associated with active
  regions with lifetimes between 11 and 80 days. They are also often
  associated with small-scale emerging or canceling flux over timescales
  of 6-7 hr. CMEs associated with active region prominence eruptions,
  on the other hand, are typically associated with old active regions
  with lifetimes ~6-7 months.

---------------------------------------------------------
Title: Reconciling Extreme-Ultraviolet and Radio Observations of
    the Sun's Corona
Authors: Zhang, J.; Kundu, M. R.; White, S. M.; Dere, K. P.; Newmark,
   J. S.
2001ApJ...561..396Z    Altcode:
  The Sun's corona, which is composed of plasma at a temperature of a few
  millions of degrees, can be best viewed in two electromagnetic domains,
  one from wavelengths of a few angstroms to hundreds of angstroms
  (in the soft X-ray and EUV domain), the other from wavelengths
  of a few centimeters to several tens of centimeters (in the radio
  domain). In this paper, we present a quantitative comparison of coronal
  observations made in these two domains with high spatial resolution
  over the full disk of the Sun. The EUV observations were taken with the
  EIT (Extreme-Ultraviolet Imaging Telescope) on board SOHO (Solar and
  Heliospheric Observatory), and the radio observations were taken with
  the VLA (Very Large Array). The two sets of images show very similar
  morphologies, indicating that the different wavelengths originate from
  common solar features. We predict radio fluxes using the temperature
  and emission measure of the corona calculated from EIT observations,
  adopting Meyer's table of coronal abundances for the calculations. In
  each of the seven observations investigated, there always exists a
  good linear correlation in the pixel-by-pixel correlation plot between
  the predicted and the observed radio flux for coronal features over a
  wide range of flux variation. Nevertheless, the predicted radio flux
  is systematically larger than that observed by a factor of 2.0+/-0.2,
  on average. We attribute the difference to the underestimation of the
  abundance of Fe relative to H in the abundances adopted by Meyer. On
  this basis, we place the absolute Fe abundance in the corona at
  7.8×10<SUP>-5</SUP>, which has an enrichment factor of 2.4 relative
  to the accepted photospheric Fe abundance.

---------------------------------------------------------
Title: CHIANTI - An atomic database for X-EUV spectral lines
Authors: Dere, K. P.; Landi, E.
2001tysc.confE..64D    Altcode:
  CHIANTI provides a database of atomic energy levels, wavelengths,
  radiative transition probabilities and electron excitation data for
  a large number of ions of astrophysical interest. It also includes
  a suite of Interactive Data Language (IDL) programs to calculate
  optically thin synthetic spectra and to perform spectral analysis
  and plasma diagnostics. This database allows the calculation of
  theoretical line emissivities necessary for the analysis of optically
  thin emission line spectra. The first version (1.01) of the CHIANTI
  database was released in 1996 h paper1. The second version, released
  in 1999, included continuum emission and data for additional ions
  (Landi et al. 1999). Both versions of the CHIANTI database have been
  used extensively by the astrophysical and solar communities to analyze
  emission line spectra from astrophysical sources. Now the CHIANTI
  database has been extended to wavelengths shorter than 50Å by including
  atomic data for the hydrogen and helium isoelectronic sequences,
  inner-shell transitions and satellite lines and several other ions. In
  addition, some of the ions already present in the database have been
  updated and extended with new atomic data from published calculations.

---------------------------------------------------------
Title: On the Temporal Relationship between Coronal Mass Ejections
    and Flares
Authors: Zhang, J.; Dere, K. P.; Howard, R. A.; Kundu, M. R.; White,
   S. M.
2001ApJ...559..452Z    Altcode:
  The temporal relationship between coronal mass ejections (CMEs) and
  associated solar flares is of great importance to understanding the
  origin of CMEs, but it has been difficult to study owing to the nature
  of CME detection. In this paper, we investigate this issue using the
  Large Angle and Spectrometric Coronagraph and the EUV Imaging Telescope
  observations combined with GOES soft X-ray observations. We present
  four well-observed events whose source regions are close to the limb
  such that we are able to directly measure the CMEs' initial evolution
  in the low corona (~1-3 R<SUB>solar</SUB>) without any extrapolation;
  this height range was not available in previous space-based coronagraph
  observations. The velocity-time profiles show that kinematic evolution
  of three of the four CMEs can be described in a three-phase scenario:
  the initiation phase, impulsive acceleration phase, and propagation
  phase. The initiation phase is characterized by a slow ascension
  with a speed less than 80 km s<SUP>-1</SUP> for a period of tens of
  minutes. The initiation phase always occurs before the onset of the
  associated flare. Following the initiation phase, the CMEs display an
  impulsive acceleration phase that coincides very well with the flares'
  rise phase lasting for a few to tens of minutes. The acceleration of
  CMEs ceases near the peak time of the soft X-ray flares. The CMEs then
  undergo a propagation phase, which is characterized by a constant speed
  or slowly decreasing in speed. The acceleration rates in the impulsive
  acceleration phase are in the range of 100-500 m s<SUP>-2</SUP>. One CME
  (on 1997 November 6, associated with an X9.4 flare) does not show an
  initiation phase. It has an extremely large acceleration rate of 7300 m
  s<SUP>-2</SUP>. The possible causes of CME initiation and acceleration
  in connection with flares are explored.

---------------------------------------------------------
Title: The Sources of Solar Ultraviolet Variability between 2765
and 2885 Å: Mg I, Mg II, Si I, and Continuum
Authors: Morrill, J. S.; Dere, K. P.; Korendyke, C. M.
2001ApJ...557..854M    Altcode:
  The variation of the solar spectrum between 2000 and 4000 Å is a
  major component of the total irradiance variability of the Sun. Recent
  analyses suggest that variations in the solar ultraviolet flux at
  these wavelengths account for about 30% of the total solar irradiance
  variability. Most estimates of solar spectral irradiance variability in
  the ultraviolet are based on the ratio of the intensity of features such
  as solar plages and sunspots to the intensity of the quiet Sun. These
  ratios are referred to as contrast factors. To a large degree, contrast
  factors at ultraviolet wavelengths have not been measured. We present
  measurements of the average intensities of plage, sunspot, and quiet-Sun
  regions in the spectral range between 2765 and 2885 Å, derived from
  high spatial and spectral resolution spectra obtained during the ninth
  rocket flight of the High Resolution Telescope and Spectrograph in
  1995. From these average spectra, plage and sunspot contrast factors
  are determined. To our knowledge, these are the first contrast factors
  at these wavelengths derived from measured solar intensities. These
  spectra show a large contrast in the Mg I, Mg II, and Si I Fraunhofer
  lines and a much smaller contrast (1.01+/-0.015 to 1.04+/-0.04) in
  the line-blanketed continuum. Contrast factors are also determined
  for three intensity levels of the quiet Sun as well as for a single
  sunspot. Many fine spectral features in the contrast factors can be
  attributed to weak Fraunhofer lines of Cr II, Fe I, Fe II, and Mg I.

---------------------------------------------------------
Title: CHIANTI-An Atomic Database for Emission Lines. IV. Extension
    to X-Ray Wavelengths
Authors: Dere, K. P.; Landi, E.; Young, P. R.; Del Zanna, G.
2001ApJS..134..331D    Altcode:
  CHIANTI provides a database of atomic energy levels, wavelengths,
  radiative transition probabilities, and electron excitation data for
  a large number of ions of astrophysical interest. It also includes a
  suite of Interactive Data Language programs to calculate optically
  thin synthetic spectra and to perform spectral analysis and plasma
  diagnostics. This database allows the calculation of theoretical line
  emissivities necessary for the analysis of optically thin emission-line
  spectra. The first version (1.01) of the CHIANTI database was released
  in 1996 and published by Dere et al. in 1997 as Paper I in this
  series. The second version, released in 1999 by Landi et al., included
  continuum emission and data for additional ions. Both versions of the
  CHIANTI database have been used extensively by the astrophysical and
  solar communities to analyze emission-line spectra from astrophysical
  sources. Now the CHIANTI database has been extended to wavelengths
  shorter than 50 Å by including atomic data for the hydrogen and helium
  isoelectronic sequences, inner-shell transitions and satellite lines,
  and several other ions. In addition, some of the ions already present
  in the database have been updated and extended with new atomic data
  from published calculations.

---------------------------------------------------------
Title: High-resolution Imaging of the Upper Solar Chromosphere:
    First Light Performance of the Very-high-Resolution Advanced
    ULtraviolet Telescope
Authors: Korendyke, C. M.; Vourlidas, A.; Cook, J. W.; Dere, K. P.;
   Howard, R. A.; Morrill, J. S.; Moses, J. D.; Moulton, N. E.; Socker,
   D. G.
2001SoPh..200...63K    Altcode:
  The Very-high-resolution Advanced ULtraviolet Telescope (VAULT)
  experiment was successfully launched on 7 May 1999 on a Black Brant
  sounding rocket vehicle from White Sands Missile Range. The instrument
  consists of a 30 cm UV diffraction limited telescope followed by a
  two-grating, zero-dispersion spectroheliograph tuned to isolate the
  solar Lα emission line. During the flight, the instrument successfully
  obtained a series of images of the upper chromosphere with a limiting
  resolution of ∼ 0.33 arc sec. The resulting observations are the
  highest-resolution images of the solar atmosphere obtained from space
  to date. The flight demonstrated that sub-arc second ultraviolet
  images of the solar atmosphere are achievable with a high-quality,
  moderate-aperture space telescope and associated optics. Herein,
  we describe the payload and its in-flight performance.

---------------------------------------------------------
Title: Solar Origin of Major Geo-magnetic Storms Between 1996 and 2000
Authors: Zhang, J.; Dere, K. P.; Howard, R. A.
2001AGUSM..SH62A11Z    Altcode:
  We investigate the solar origin of major geo-magnetic storms which
  occurred between 1996 and 2000. Based on the hourly DST index, we
  identify 39 major geo-magnetic storms (defined as peak DST less
  than -100) in this period. The solar observations are primarily
  based on LASCO (Large-Angle and Spectrometric Coronagraph) and EIT
  (Extreme-ultraviolet Imaging Telescope) instruments on board SOHO
  spacecraft. Using a six-day time window, we search through all
  halo/partial-halo CMEs (Coronal Mass Ejections) seen in LASCO and
  coronal dimmings seen in EIT for each storm to try to identify its
  solar source. 30 of the 39 storms are in the LASCO/EIT duty cycle
  (most of the other 9 events occurred during 1998-1999 SOHO failure). We
  associate these storms to solar sources with three different confidence
  levels. For 18 of the 30 events, we have reliably determined their solar
  sources, all of which show both strong halo CME signature and almost
  simultaneous strong coronal dimming signature; these signatures are
  usually unique in the time window. For 5 of the 30 events, there are
  multiple halo CMEs and dimmings found in the time window, and we can
  not make unambiguous association with a particular solar source. For
  the other 7 of the 30 events, we find it is difficult to identify
  solar sources, due to lack of strong signature in either LASCO or
  EIT observations or both. We investigate various characteristics of
  solar sources for those 18 major storms with unambiguous association,
  including CME morphology and kinematics, pre-eruption coronal structure
  and evolution, coronal dimmings and waves, coronal post-eruption loops,
  X-ray and optical flares, filaments, photospheric magnetic field
  structure and distribution of heliocentric position. The purpose is
  to understand the characteristics of CMEs observed near the Sun which
  causes major geo-magnetic storms.

---------------------------------------------------------
Title: Ultra-High Resolution Observations of the Upper Chromosphere:
    First Results From the NRL VAULT Sounding Rocket Payload
Authors: Vourlidas, A.; Korendyke, C. M.; Dere, K. P.; Klimchuk, J. A.
2001AGUSM..SP61A03V    Altcode:
  The Very high resolution Advanced ULtraviolet Telescope (VAULT) is
  a new spectroscopic imaging instrument. The instrument was launched
  on May 7, 1999 as a sounding rocket payload. The goal of the first
  VAULT flight was to obtain sub-arcsecond images of the Sun in the
  light of Lya (1216 Å). VAULT directly imaged an active region plage,
  fliaments and the fine structures in the supergranule boundaries and
  network with the unprecented spatial resolution of 0.33 arcseconds. We
  present the VAULT images and the first results from the comparison of
  the Lya data to observations from other instruments and in particular
  with a sequence of TRACE 171 Å images taken during the VAULT flight.

---------------------------------------------------------
Title: CHIANTI - an atomic database for emission lines, Paper 4:
    Extension to X-ray Wavelengths
Authors: Dere, K. P.; Landi, E.; Young, P. R.; Del Zanna, G.
2001AGUSM..SP21B08D    Altcode:
  CHIANTI provides a database of atomic energy levels, wavelengths,
  radiative transition probabilities and electron excitation data for
  a large number of ions of astrophysical interest. It also includes
  a suite of Interactive Data Language (IDL) programs to calculate
  optically thin synthetic spectra and to perform spectral analysis and
  plasma diagnostics. This database allows the calculation of theoretical
  line emissivities necessary for the analysis of optically thin emission
  line spectra. The first version of the CHIANTI database was released
  in 1996 (Dere et al., 1996). The second version, released in 1999,
  included continuum emission and data for additional ions (Landi
  et al. 1999). Both versions of the CHIANTI database have been used
  extensively by the astrophysical and solar communities to analyze
  emission line spectra from astrophysical sources. Now the CHIANTI
  database has been extended to wavelengths shorter than 50Å by including
  atomic data for the hydrogen and helium isoelectronic sequences,
  inner-shell transitions and satellite lines and several other ions. In
  addition, some of the ions already present in the database have been
  updated and extended with new atomic data from published calculations.

---------------------------------------------------------
Title: The Extreme Ultraviolet Imaging Spectrometer on Solar-B
Authors: Mariska, J. T.; Brown, C. M.; Dere, K. P.; Doschek, G. A.;
   Korendyke, C. M.; Culhane, J. L.; Watanabe, T.
2001AGUSM..SH41A12M    Altcode:
  Emission lines in the extreme ultraviolet spectral region provide a
  sensitive probe of the high-temperature plasma in the solar transition
  region and corona. Simultaneously achieving high spatial, spectral, and
  temporal resolution in this wavelength region has been challenging. We
  describe the design and capabilities of the Extreme Ultraviolet
  Imaging Spectrometer (EIS) planned for flight on the Japanese Solar-B
  satellite. EIS consists of a multilayer-coated off-axis telescope
  mirror and a multilayer-coated toroidal grating spectrometer. The
  telescope mirror forms a solar image on the spectrometer entrance slit
  assembly and the spectrometer forms stigmatic spectra of the solar
  region isolated by the 1024 arcsec high slit. The instrument includes
  thin-film aluminum filters to reject longer wavelength radiation and
  CCD detectors at the focal plane. Articulation of the primary mirror
  provides roughly 1600 arcsec of east-west coarse pointing freedom
  and 360 arcsec of fine east-west motion for rastering. Monochromatic
  images are formed either by rastering the solar image across a narrow
  entrance slit or by using a very wide slit. Half of each optic is
  coated to optimize reflectance at 19.5 nm, and the other half to
  optimize reflectance at 27.0 nm. Each wavelength range is imaged onto
  a separate CCD detector. The EIS spectral range contains emission lines
  formed over a temperature range from roughly 0.1 to 20 MK. Bright lines
  in the selected wavelength bands will yield precision measurements of
  line-of-sight velocities and nonthermal plasma motions. This spectral
  range also includes several pairs of density-sensitive lines.

---------------------------------------------------------
Title: High Resolution Observations of Solar Spectral Variability
    Near Mg II Measured by HRTS
Authors: Morrill, J. S.; Dere, K. P.; Korendyke, C. M.
2001AGUSM..SP32B03M    Altcode:
  The HRTS-9 rocket flight occurred on April 18, 1995 and made
  measurements of solar spectral variability near the Mg II h and k
  lines. These observations include high spatial and spectral resolution
  spectrograms as well as spectroheliograms in four FUV passbands and
  H-alpha. The spectrograms cover the wavelength range 2665 to 2885Å
  with a spectral resolution of .2Å and a spatial resolution of 1
  arc-second along a 900 arc-second slit. The most prominent features
  in this spectral range include the strong Mg II h and k lines near
  2800 Å, the Mg I and Si I Fraunhofer lines near 2850 and 2880Å,
  respectively, and the line-blanketed quasi-continuum region. During
  the HRTS-9 flight, spectrograms and spectroheliograms where obtained
  of the quiet sun, quiet limb, plage, and sunspots. In addition to
  instrumental corrections, we have recently applied an absolute intensity
  calibration to the HRTS-9 data derived from SUSIM/ATLAS-3 and SUSIM/UARS
  observations. The analysis of these calibrated data has focused on
  the spectral variability of the above surface features and how these
  observations impact solar irradiance variability. Specifically, we
  examine the contrast variation of the plage and sunspot compared to the
  quiet sun as well as contrast variation within the quiet sun. In this
  presentation we will discuss the details of the observed spectra and
  wavelength dependent contrast factors. This will include a comparison
  of our present results with earlier estimates of plage contrast in this
  wavelength region and a discussion of the fine structures observed at
  high spectral resolution.

---------------------------------------------------------
Title: Source Regions of Coronal Mass Ejections
Authors: Dere, K. P.; Subramanian, P.
2001IAUS..203..362D    Altcode:
  A set of 32 coronal mass ejections observed with the LASCO and EIT
  instruments on SOHO have been examined. These events have been selected
  from the period between May 1997 through May 1998 and includes the
  period of solar minimum and the rise of solar cycle 23. The criteria
  for including these events were that they were observed as a CME
  in LASCO, they were well observed with EIT and they were located
  near disk center. The sources of these 32 events were active regions
  without filaments (26 cases),active regions with filaments (7 cases)
  and quiescent filaments (6 cases). In the EIT, the signature of the
  initiation of the coronal mass ejection includes flares, EIT waves,
  coronal dimmings and mass ejections. The characteristics of the
  photospheric magnetic activity associated with these events, observed
  with NSO/Kitt Peak and MDI/SOHO magnetograms, indicate that CMEs are
  associated with a wide range of activity that includes small scale
  flux emergence and cancellation, large scale flux emergence, and large
  scale flux decay. During this period of the solar cycle, the solar disk
  contains few active regions which are generally generally short lives
  so that there may be a solar cycle dependence to these conclusions.

---------------------------------------------------------
Title: BEPPOSAX Observation of EQ Pegasi (CD-ROM Directory:
    contribs/landi)
Authors: Landi, E.; Landini, M.; Dere, K.; Risaliti, G.
2001ASPC..223..991L    Altcode: 2001csss...11..991L
  No abstract at ADS

---------------------------------------------------------
Title: In-flight performance of the Very high Angular resolution
    ULtraviolet Telescope sounding rocket payload
Authors: Korendyke, Clarence M.; Vourlidas, A.; Cook, John W.; Dere,
   Kenneth P.; Feldman, R.; Howard, Russell A.; Lilley, D. N.; Morrill,
   Jeff S.; Moses, J. Daniel; Moulton, Norman E.; Moye, Robert W.;
   Roberts, D. E.; Shepler, E. L.; Smith, J. K.; Socker, Dennis G.;
   Spears, T. R.; Waymire, R. S.; Brown, Wayne E.; Tarbell, Theodore D.;
   Berger, Tom; Handy, Brian N.
2000SPIE.4139..340K    Altcode:
  The Very high Angular Resolution ULtraviolet Telescope experiment was
  successfully launched on May 7, 1999 on a Black Brant sounding rocket
  vehicle from White Sands Missile Range. The instrument consists of a
  30 cm UV diffraction limited telescope followed by a double grating
  spectroheliograph tuned to isolate the solar Lyman (alpha) emission
  line. During the flight, the instrument successfully obtained a series
  of images of the upper chromosphere with a limiting resolution of
  approximately 0.33 arc-seconds. The resulting observations are the
  highest resolution images of the solar atmosphere obtained from space
  to date. The flight demonstrated that subarc-second ultraviolet images
  of the solar atmosphere are achievable with a high quality, moderate
  aperture space telescope and associated optics. Herein, we describe
  the payload and its in- flight performance.

---------------------------------------------------------
Title: Solar Transition Region
Authors: Dere, K.
2000eaa..bookE2021D    Altcode:
  The solar transition region can generally be defined as those
  plasmas at temperatures between 2×104 and 1×106 K, a temperature
  regime bridging the CHROMOSPHERE and CORONA. Prior to the space age,
  the transition region was unobserved although the existence of the
  higher-temperature corona was known. Spectral lines formed at transition
  region temperatures are found primarily below 2000 Å where they...

---------------------------------------------------------
Title: The Preflight Photometric Calibration of the
    Extreme-Ultraviolet Imaging Telescope EIT
Authors: Dere, K. P.; Moses, J. D.; Delaboudinière, J. -P.; Brunaud,
   J.; Carabetian, C.; Hochedez, J. -F.; Song, X. Y.; Catura, R. C.;
   Clette, F.; Defise, J. -M.
2000SoPh..195...13D    Altcode:
  This paper presents the preflight photometric calibration of the
  Extreme-ultraviolet Imaging Telescope (EIT) aboard the Solar and
  Heliospheric Observatory (SOHO). The EIT consists of a Ritchey-Chrétien
  telescope with multilayer coatings applied to four quadrants of the
  primary and secondary mirrors, several filters and a backside-thinned
  CCD detector. The quadrants of the EIT optics were used to observe
  the Sun in 4 wavelength bands that peak near 171, 195, 284, and 304
  Å. Before the launch of SOHO, the EIT mirror reflectivities, the filter
  transmissivities and the CCD quantum efficiency were measured and these
  values are described here. The instrumental throughput in terms of an
  effective area is presented for each of the various mirror quadrant
  and filter wheel combinations. The response to a coronal plasma as
  a function of temperature is also determined and the expected count
  rates are compared to the count rates observed in a coronal hole,
  the quiet Sun and an active region.

---------------------------------------------------------
Title: Solar UV Irradiance Variability Observed at High Spatial and
    Spectral Resolution by HRTS
Authors: Morrill, J. S.; Dere, K. P.; Korendyke, C. M.
2000SPD....31.0128M    Altcode: 2000BAAS...32..806M
  The HRTS-9 rocket flight occured on April 18, 1995 and was configured
  to study the sources of solar variablity by observing ultraviolet
  emission patterns near the Mg II h and k lines. These observations
  include high spatial and spectral resolution spectrograms as
  well as spectroheliograms in four FUV passbands and H-alpha. The
  spectrograms cover the wavelength range 2665 to 2885 Angstroms \ with
  a spectral resolution of .2 Angstroms \ and a spatial resolution of 1
  arc-second along a 900 arc-second slit. Prominent spectral features
  in this wavelength range include the Mg II h and k lines near 2800
  Angstroms, the strong Mg I and Si I Fraunhofer lines near 2850 and
  2880 Angstroms, respectively, and the line-blanketed quasi-continuum
  region. HRTS-9 observations included the quiet sun, quiet limb,
  plage, and sunspots. The analysis of this data set has focused on
  the spatial intensity variability of the features as a function of
  wavelength with particular regard for how these will affect solar
  variability. Specifically, we examine the contrast variation of
  the plage and sunspot compared to the quiet sun as well as contrast
  variation within the quiet sun. The observed sunspot spectrum shows
  the characteristic decrease in the quasi-continuum, the non-reversed
  Mg II h and k line shapes as well as the enhancement in the Mg II
  h and k core emissions over that observed in the quiet sun. In this
  presentation we will discuss the wavelength dependent contrasts of
  the plage and quiet sun regions, the characteristics of the observed
  sunspot spectrum, and the implications on solar variability.

---------------------------------------------------------
Title: Large-Angle Spectrometric Coronagraph Measurements of the
    Energetics of Coronal Mass Ejections
Authors: Vourlidas, A.; Subramanian, P.; Dere, K. P.; Howard, R. A.
2000ApJ...534..456V    Altcode:
  We examine the energetics of coronal mass ejections (CMEs) with data
  from the large-angle spectrometric coronagraphs (LASCO) on SOHO. The
  LASCO observations provide fairly direct measurements of the mass,
  velocity, and dimensions of CMEs. Using these basic measurements,
  we determine the potential and kinetic energies and their evolution
  for several CMEs that exhibit flux-rope morphologies. Assuming flux
  conservation, we use observations of the magnetic flux in a variety
  of magnetic clouds near the Earth to determine the magnetic flux and
  magnetic energy in CMEs near the Sun. We find that the potential and
  kinetic energies increase at the expense of the magnetic energy as
  the CME moves out, keeping the total energy roughly constant. This
  demonstrates that flux-rope CMEs are magnetically driven. Furthermore,
  since their total energy is constant, the flux-rope parts of the CMEs
  can be considered a closed system above ~2 R<SUB>solar</SUB>.

---------------------------------------------------------
Title: LASCO and EIT observations of CMEs associated with flares
Authors: Zhang, J.; Dere, K. P.; Howard, R. A.; Kundu, M. R.; White,
   S. M.
2000SPD....31.0906Z    Altcode: 2000BAAS...32..841Z
  Coronal mass ejections (CME) and flares are two primary causes
  of adverse space weather. These two solar eruptive phenomenon are
  often observed to be associated with each other. Yet the relationship
  between them is not well known. With unprecedented LASCO (Large-Angle
  and Spectrometric Coronagraph) and EIT (Extreme-ultraviolet Imaging
  Telescope) observations combined with simultaneous HXT (Hard X-ray
  Telescope), GOES and other flare observations, we pursue to make a
  comprehensive study on the spatial, temporal and energetic relationship
  between CMEs and flares. In order to make accurate measurement of the
  onset time of CMEs, we primarily select CME events whose source regions
  are close to the limb and which are well observed by LASCO/C1 from
  1.1 to 3 solar radii. Although a flare occurs in a rather small area
  of active region, the CME's source region often covers much larger
  longitudinal and latitudinal extension. Some CMEs occur simultaneously
  with flare (within only a few minutes), however, some CMEs occur
  well before the flares (more than 30 minutes earlier). Fast CMEs are
  associated with strong flares. These studies are aimed to understand
  the initiation process of solar eruptive phenomenon, and to fit a
  variety of observational aspects into a consistent picture.

---------------------------------------------------------
Title: LASCO and EIT Observations of Coronal Mass Ejections
Authors: Dere, K. P.; Vourlidas, A.; Subramanian, Prasad
2000astro.ph..2061D    Altcode:
  We present a brief overview of LASCO and EIT observations of CMEs. We
  discuss CME energetics, the relation of CMEs to streamers and conclude
  with some insights into the source regions of CMEs.

---------------------------------------------------------
Title: Non-Radial Unipolar Coronal Streamers in Magnetically High
    Latitudes and Radial Bipolar Streamers at the Magnetic Equator of
    the Sun
Authors: Saito, Takao; Shibata, K.; Dere, K. P.; Numazawa, S.
2000AdSpR..26..807S    Altcode:
  The complex structure of coronal streamers can be better understood by
  their classification into two classes: non-radial unipolar streamers
  emanating from magnetically high latitudes, and radial bipolar streamers
  emanating from the magnetic equator. The coronal streamers observed
  during the total solar eclipses of July 11,1991 and February 26, 1998
  are classified into the two types. Various characteristics of the two
  types are discussed and summarized. Important relations of the two to
  solar, interplanetary, and terrestrial phenomena are discussed

---------------------------------------------------------
Title: Coronal Mass Ejections and the Solar Wind: New Results
    from LASCO
Authors: Dere, K. P.; Howard, R. A.; Brueckner, G. E.
2000AdSpR..25.1837D    Altcode:
  The LASCO and EIT experiments on SOHO have provided a revolutionary
  picture of coronal dynamics. In the past, the corona has largely been
  thought to be a region where the evolution of the coronal structures
  occurred on relatively large time scales, aside from the intermittent
  coronal mass ejection. The outflows in the polar coronal holes were
  largely considered to be time-independent. The picture now presented by
  the LASCO and EIT observations are of a highly dynamic corona. Continual
  small scale sporadic outflows are observed in quiet streamers and
  in the polar coronal holes. The LASCO images of CMEs shows that many
  appear to have circular structures that indicate that they consist of
  helical magnetic flux ropes. In addition, a new class of CMEs has been
  observed and are called `global' CMEs since they appear to involve
  regions of the corona separated by as much as 180°

---------------------------------------------------------
Title: Commission 10: Solar Activity: (Activite Solaire)
Authors: Ai, G.; Benz, A.; Dere, K. P.; Engvold, O.; Gopalswamy, N.;
   Hammer, R.; Hood, A.; Jackson, B. V.; Kim, I.; Marten, P. C.; Poletto,
   G.; Rozelot, J. P.; Sanchez, A. J.; Shibata, K.; van Driel-Geztelyi, L.
2000IAUTA..24...67A    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Microwave and Extreme Ultraviolet Observations of Solar
    Polar Regions
Authors: Nindos, A.; Kundu, M. R.; White, S. M.; Gary, D. E.;
   Shibasaki, K.; Dere, K. P.
1999ApJ...527..415N    Altcode:
  The poles of the Sun are brighter than the rest of the quiet Sun's
  emission in a limited range of radio frequencies from 17 GHz to 87
  GHz. We have studied microwave images of the quiet Sun made with
  the Nobeyama radioheliograph at 17 GHz. They show that the so-called
  polar-cap brightening consists of two components: a diffuse component
  of 1500 K excess brightness and patchy compact sources with localized
  excess brightness of about 3500 K. We test the reality of the compact
  sources using the maximum entropy method deconvolution. The total flux
  and the number of compact polar sources as well as the north-south
  extent of the diffuse polar emission are larger in the pole that is
  closest to the Earth. We compared the microwave polar emission with
  nearly simultaneous SOHO EIT images taken in the lines of He II at 304
  Å and Fe XII at 195 Å. No one-to-one correlation between the compact
  radio sources and the bright EUV features was found: most of the radio
  emission arises between the plumes visible to EIT. The boundaries of
  the polar-cap brightenings did not match exactly the boundaries of the
  coronal holes as seen in either the Fe XII 195 Å images or the He II
  304 Å images. The temporal variations of the compact microwave sources
  did not correspond to any significant changes in EUV emission. On the
  other hand, most He II 304 Å changing features were associated with the
  diffuse polar microwave emission, which was practically constant. Our
  data suggest that the origin of the polar brightening is not coronal;
  it seems that the bulk of the patchy radio emission comes from heights
  below the 80,000 K layer.

---------------------------------------------------------
Title: LASCO Measurements of the Energetics of Coronal Mass Ejections
Authors: Vourlidas, Angelos; Subramanian, Prasad; Dere, K. P.; Howard,
   R. A.
1999astro.ph.12069V    Altcode:
  We examine the energetics of Coronal Mass Ejections (CMEs) with data
  from the LASCO coronagraphs on SOHO. The LASCO observations provide
  fairly direct measurements of the mass, velocity and dimensions of
  CMEs. Using these basic measurements, we determine the potential and
  kinetic energies and their evolution for several CMEs that exhibit a
  flux-rope morphology. Assuming flux conservation, we use observations
  of the magnetic flux in a variety of magnetic clouds near the Earth
  to determine the magnetic flux and magnetic energy in CMEs near the
  Sun. We find that the potential and kinetic energies increase at the
  expense of the magnetic energy as the CME moves out, keeping the total
  energy roughly constant. This demonstrates that flux rope CMEs are
  magnetically driven. Furthermore, since their total energy is constant,
  the flux rope parts of the CMEs can be considered to be a closed system
  above $\sim$ 2 $R_{\sun}$.

---------------------------------------------------------
Title: CHIANTI: A database for astrophysical emission line
    spectroscopy
Authors: Del-Zanna, Giulio; Young, Peter; Dere, Ken; Landini, Massimo;
   Landi, Enrico; Mason, Helen
1999ascl.soft11004D    Altcode:
  CHIANTI consists of a critically evaluated set of atomic data necessary
  to calculate the emission line spectrum of astrophysical plasmas. The
  data consists of atomic energy levels, atomic radiative data such as
  wavelengths, weighted oscillator strengths and A values, and electron
  collisional excitation rates. A set of programs that use these data to
  calculate the spectrum in a desired wavelength range as a function of
  temperature and density are also provided. These programs have been
  written in Interactive Data Language (IDL) and descriptions of these
  various programs are provided on the website.

---------------------------------------------------------
Title: Concept Study Report: Extreme-Ultraviolet Imaging Spectrometer
    Solar-B
Authors: Doschek, George A.; Brown, Charles M.; Davila, Joseph M.;
   Dere, Kenneth P.; Korendyke, Clarence M.; Mariska, John T.; Seely,
   John F.
1999STIN...0011153D    Altcode:
  We propose a next generation Extreme-ultraviolet Imaging Spectrometer
  (EIS) that for the first time combines high spectral, spatial, and
  temporal resolution in a single solar spectroscopic instrument. The
  instrument consists of a multilayer-coated off-axis telescope mirror
  and a multilayer-coated grating spectrometer. The telescope mirror
  forms solar images on the spectrometer entrance slit assembly. The
  spectrometer forms stigmatic spectra of the solar region located
  at the slit. This region is selected by the articulated telescope
  mirror. Monochromatic images are obtained either by rastering the solar
  region across a narrow entrance slit, or by using a very wide slit
  (called a slot) in place of the slit. Monochromatic images of the
  region centered on the slot are obtained in a single exposure. Half
  of each optic is coated to maximize reflectance at 195 Angstroms; the
  other half to maximize reflectance at 270 Angstroms. The two Extreme
  Ultraviolet (EUV) wavelength bands have been selected to maximize
  spectral and dynamical and plasma diagnostic capabilities. Spectral
  lines are observed that are formed over a temperature range from about
  0.1 MK to about 20 MK. The main EIS instrument characteristics are:
  wavelength bands - 180 to 204 Angstroms; 250 to 290 Angstroms; spectral
  resolution - 0.0223 Angstroms/pixel (34.3km/s at 195 Angstroms and
  23.6 km/s at 284 Angstroms); slit dimensions - 4 slits, two currently
  specified dimensions are 1" x 1024" and 50" x 1024" (the slot);
  largest spatial field of view in a single exposure - 50" x 1024";
  highest time resolution for active region velocity studies - 4.4 s.

---------------------------------------------------------
Title: The relationship of coronal mass ejections to streamers
Authors: Subramanian, Prasad; Dere, K. P.; Rich, N. B.; Howard, R. A.
1999JGR...10422321S    Altcode: 1999astro.ph..6207S
  We have examined images from the Large-Angle and Spectrometric
  Coronagraph (LASCO) to study the relationship of coronal mass ejections
  (CMEs) to coronal streamers. We wish to test the suggestion [Low,
  1996] that CMEs arise from flux ropes embedded in a streamer erupting
  and disrupting the streamer. The data span a period of 2 years near
  Sunspot minimum through a period of increased activity as Sunspot
  numbers increased. We have used LASCO data from the C2 coronagraph
  which records Thomson scattered white light from coronal electrons at
  heights between 1.5 and 6R<SUB>s</SUB>. Maps of the coronal streamers
  have been constructed from LASCO C2 observations at a height of
  2.5R<SUB>s</SUB> at the east and west limbs. We have superposed the
  corresponding positions of CMEs observed with the C2 coronagraph onto
  the synoptic maps. We identified the different kinds of signatures CMEs
  leave on the streamer structure at this height (2.5R<SUB>s</SUB>). We
  find four types of CMEs with respect to their effect on streamers:
  1. CMEs that disrupt the streamer, 2. CMEs that have no effect on
  the streamer, even though they are related to it, 3. CMEs that create
  streamer-like structures and 4. CMEs that are latitudinally displaced
  from the streamer. CMEs in categories 3 and 4 are not related to the
  streamer structure. This is the most extensive observational study
  of the relation between CMEs and streamers to date. Previous studies
  using SMM data have made the general statement that CMEs are mostly
  associated with streamers and that they frequently disrupt it. However,
  we find that approximately 35% of the observed CMEs bear no relation
  to the preexisting streamer, while 46% have no effect on the observed
  streamer, even though they appear to be related to it. Our conclusions
  thus differ considerably from those of previous studies.

---------------------------------------------------------
Title: SOHO/EIT Observations of the 1997 April 7 Coronal Transient:
    Possible Evidence of Coronal Moreton Waves
Authors: Thompson, B. J.; Gurman, J. B.; Neupert, W. M.; Newmark,
   J. S.; Delaboudinière, J. -P.; Cyr, O. C. St.; Stezelberger, S.;
   Dere, K. P.; Howard, R. A.; Michels, D. J.
1999ApJ...517L.151T    Altcode:
  We report observations obtained with the Extreme ultraviolet
  Imaging Telescope (EIT) on board SOHO of a large-scale coronal
  transient propagating across the disk of the Sun at a speed of 250 km
  s<SUP>-1</SUP>, in apparent association with a flare and coronal mass
  ejection. The observations consist of a series of images taken in the
  Fe XII 195 Å bandpass at an average cadence of 15 minutes. A visible
  increase in coronal emission propagates away from the erupting region,
  traveling across most of the solar disk in less than an hour. As the
  wave propagates through the ambient corona, its path is not homogeneous,
  and it is less observable near strong magnetic features such as
  active regions and magnetic neutral lines. The characteristics of
  this event appear to be representative of several other “EIT waves,”
  which we identify as strong candidates for the coronal manifestation
  of Moreton waves.

---------------------------------------------------------
Title: Microwave and Extreme Ultraviolet Observations of Solar
    Polar Regions
Authors: Nindos, A.; Kundu, M. R.; White, S. M.; Gary, D. E.;
   Shibasaki, K.; Dere, K. P.
1999AAS...194.3207N    Altcode: 1999BAAS...31..871N
  The radio emission of solar poles is brighter than the rest of the
  quiet Sun's emission in a limited range of frequencies from 17 GHz to
  87 GHz. We have studied microwave images of the quiet Sun made with
  the Nobeyama Radioheliograph at 17 GHz. They show that the so-called
  polar-cap brightening consists of two components: a diffuse component
  of 1500 K excess brightness, and patchy compact sources with localized
  excess brightness of about 3500 K. The total flux and the number of
  compact polar sources as well as the North-South extent of the diffuse
  polar emission are larger in the pole which is closest to the Earth. We
  compared the microwave polar emission with nearly simultaneous SoHO EIT
  images taken in the lines of He ii at 304 Angstroms and Fe xii at 195
  Angstroms. No one-to-one correlation between the compact radio sources
  and the bright EUV features was found: most of the radio emission arises
  between the plumes visible to EIT. The boundaries of the polar-cap
  brightenings did not match exactly the boundaries of the coronal holes
  as seen in the Fe xii 195 Angstroms images. The temporal variations of
  the compact microwave sources did not correspond to any significant
  changes in EUV emission. On the other hand, most He ii 304 Angstroms
  changing features were associated with the diffuse polar microwave
  emission which was practically constant. Our data suggest that the
  origin of the polar brightening is not coronal; it seems that the bulk
  of the patchy radio emission comes from heights below the 80000 K layer.

---------------------------------------------------------
Title: LASCO Measurements of Erupting Flux Ropes
Authors: Vourlidas, A.; Subramanian, P.; Dere, K. P.; Howard, R. A.
1999AAS...19410103V    Altcode: 1999BAAS...31..998V
  It is commonly assumed that Coronal Mass Ejections from the Sun are
  magnetically driven. We address this question with data from the LASCO
  coronagraphs aboard the SOHO spacecraft. These observations provide
  fairly direct measurements of the energetics of CMEs. We determine
  the kinetic and gravitational energies and their evolution for several
  helical CMEs. We estimate the evolution of the magnetic energy based on
  the conservation of magnetic flux and observations of magnetic clouds
  near the Earth. From the magnitude and variation of these three forms
  of energy, we examine the energetics of CMEs from the perspective that
  they are driven through their internal magnetic energy.

---------------------------------------------------------
Title: Global Coronal Mass Ejections observed with LASCO
Authors: Dere, K. P.; Howard, R. A.
1999AAS...19410101D    Altcode: 1999BAAS...31..998D
  The Large Angle Spectrometric Coronagraph (LASCO) on the Solar
  and Heliospheric Observatory (SOHO) spacecraft has provide nearly
  continuous observations of the solar corona from January 1996 until the
  present. This covers periods near minimum solar activity through the
  rise of the current sunspot cycle. Numerous coronal mass ejections
  (CMEs) have been observed during this period. Many of these can
  be characterized as arising from a spatially limited area of the
  corona. However, there now appears to be a class of CMEs that involve
  involve coronal structures spanning a hemisphere or more and we refer
  to these CMEs as global CMEs. In some cases, simultaneous CME activity
  are seen above the limb on opposite sides of the solar disk. Several
  examples of global CMEs are presented. The fact that they can occur
  during periods of relatively low solar activity supports the sugestion
  that these large scale CMEs are not simply the chance occurence of 2
  or more unrelated CMEs at about the same time.

---------------------------------------------------------
Title: HRTS Observations of Solar Fine Scale Structures in the Near-UV
Authors: Morrill, J. S.; Dere, K. P.; Korendyke, C. M.
1999AAS...194.9311M    Altcode: 1999BAAS...31..990M
  The NRL High Resolution Telescope and Spectrograph (HRTS) obtains
  ultraviolet spectra, ultraviolet spectroheliograms and H alpha
  spectroheliograms at a spatial resolution of about 1 arc-second along
  a 900 arc-second slit. The HRTS-9 rocket flew on April 18, 1995 during
  the declining phase of the solar cycle. The HRTS-9 instrument and
  observing program were tailored to observe emission patterns inthe
  ultraviolet for the purpose of studying solar variability. Observation
  targets included the quiet sun, active regions and the quiet limb. The
  wavelength range of HRTS-9 spectrograph was from 275 nm to 290 nm. Some
  of the prominent spectral features in this wavelength range are the
  Mg II h and k lines at 280 nm, the strong Mg I Fraunhofer line at 285
  nm, and the continuum. The ultraviolet spectroheliograph obtained
  images of a portion of the sun at wavelengths corresponding to a
  range of temperatures: 1550 (C IV), 1540 (Si I), 1560 (C I), and 1600
  (continuum). The primary goal of the HRTS-9 rocket program was to
  examine the origin of the total solar variability in the intensity
  variations of solar structures in the near ultraviolet on a variety
  of spatial scales. The HRTS-9 data reveals the fine structure of the
  quiet sun, plage, and sun spots in the near ultraviolet. In addition,
  active region contrast factors are determined for comparison with
  modes of full disk ultraviolet variability based on SUSIM and SOLTICE
  observations from UARS.

---------------------------------------------------------
Title: The Increase in Mass of CMEs due to Propagation
Authors: Howard, R. A.; Dere, K. P.; Sheeley, N. R., Jr.; Subramanian,
   P.; Vourlidas, A.; Wang, D.
1999AAS...19410102H    Altcode: 1999BAAS...31..998H
  The question we would like to address is whether coronal mass ejections
  snowplow ambient material. Some of the CMEs observed by the LASCO
  coronagraph on SOHO have a clearly defined loop-like front, meaning
  that the trailing edge of the front can be clearly defined. We measure
  the mass in the front of the CME in this subclass. We find that for
  some of the events, the mass in the leading edge increases, implying
  that the CME is indeed "snowplowing" ambient material. If there is a
  significant increase in mass, then the CME frontal speed might decrease
  to conserve momentum. We estimate the amount of ambient material,
  using a model of coronal densities, and find that it is consistent
  with the mass increase. We can also estimate the height in the corona,
  below the occulting disk, from where the original material in the CME
  is released. These concepts as well as conditions for when the mass
  increases will be discussed.

---------------------------------------------------------
Title: Solar Polar Imager
Authors: Moses, D.; Dere, K. P.; Howard, R. A.; Korendyke, C. M.;
   Socker, D. G.; Wang, Y. -M.; Goldstein, B. E.; Liewer, P. E.
1999AAS...194.7613M    Altcode: 1999BAAS...31..958M
  Observation of the global coronal and magnetic field structure of
  the Sun requires coronal imaging and magnetograms from a perspective
  out of the ecliptic. While the upcoming Solar Terrestrial Relations
  Observatory (STEREO) mission will provide a great advance in the
  understanding of the three-dimensional structure of the corona and
  interplanetary medium, the orientation of the Sun's large scale magnetic
  axis of symmetry with the STEREO spacecraft separation defines the
  limits of this mission. The global structure of the streamer belts,
  polar coronal holes and coronal plumes all reflect the symmetry of
  the large scale solar magnetic field. Observations of Coronal Mass
  Ejections (CMEs) from the LASCO and EIT instruments on the Solar and
  Heliospheric Observatory (SOHO) indicate the need for synoptic coronal
  imaging out of the ecliptic (Solar Polar Imager), as well as in stereo
  pairs in the ecliptic (STEREO), for advancement in the understanding
  of the origins and consequences of CMEs. The SOHO MDI has shown the
  need for observations of the evolution of the polar magnetic fields
  and convection patterns to understand the generation and transport
  of the solar magnetic fields. Finally, the Ulysses mission has shown
  the need for polar coronal imaging and magnetograms for understanding
  the source of the solar wind. Ulysses has demonstrated the need for
  on-board in situ particles and fields instruments as a link to the
  remote sensing observations. Lightweight and compact instrumentation for
  these observations has already been demonstrated technically. An orbital
  mission involving a Jupiter assist such as Ulysses is also technically
  demonstrated, although the duration of the polar observations is limited
  to the point of degrading the studies of solar cycle evolution. An
  orbital mission involving a circularized polar orbit is possible with
  the use of solar-sail propulsion, but this involves technology that
  has yet to be demonstrated.

---------------------------------------------------------
Title: LASCO and EIT Observations of Helical Structure in Coronal
    Mass Ejections
Authors: Dere, K. P.; Brueckner, G. E.; Howard, R. A.; Michels, D. J.;
   Delaboudiniere, J. P.
1999ApJ...516..465D    Altcode:
  Observations of coronal mass ejections (CMEs) by the Large Angle
  Spectrometric Coronagraph (LASCO) on the Solar and Heliospheric
  Observatory (SOHO) show a significant fraction with circular intensity
  patterns. In the past, these would have been called “disconnection”
  events, but we suggest that these are evidence of CMEs containing
  helical magnetic flux ropes that are often central to many theoretical
  models of CMEs and have been observed in magnetic clouds near
  1 AU. Three examples are examined in detail with the LASCO and
  Extreme-Ultraviolet Imaging Telescope (EIT) data sets, which provide
  observations from their initiation through 30 R<SUB>solar</SUB>.

---------------------------------------------------------
Title: CHIANTI - an atomic database for emission lines. III. Continuum
    radiation and extension of the ion database
Authors: Landi, E.; Landini, M.; Dere, K. P.; Young, P. R.; Mason,
   H. E.
1999A&AS..135..339L    Altcode:
  CHIANTI provides a database of atomic energy levels, wavelengths,
  radiative transition probabilities and electron excitation data for a
  large number of ions of astrophysical interest. This database allows
  the calculation of theoretical line emissivities necessary for the
  analysis of optically thin emission line spectra, and includes also
  a suite of IDL (Interactive Data Language) programs to calculate
  optically thin synthetic spectra and to perform spectral analysis and
  plasma diagnostics. The first version (1.0) of the CHIANTI database was
  released in 1996 te[(Dere et al. 1997)]{Der97} and has been extensively
  used for analysis of line spectra from astrophysical sources by the
  scientific community. The present paper describes the first major update
  to the CHIANTI database which will subsequently be labeled version
  2.0. The update consists of the addition of a large number of new ions,
  the revision of existing data for some ions and the inclusion of an
  IDL procedure to calculate the continuum. The CHIANTI atomic database
  and supporting IDL routines are freely available through the internet.

---------------------------------------------------------
Title: Observations of Coronal Structures Above an Active Region by
    EIT and Implications for Coronal Energy Deposition
Authors: Neupert, W. M.; Newmark, J.; Delaboudinière, J. -P.;
   Thompson, B. J.; Catura, R. C.; Moses, J. D.; Gurman, J. B.;
   Portier-Fozzani, F.; Gabriel, A. H.; Artzner, G.; Clette, F.; Cugnon,
   P.; Maucherat, A. J.; Defise, J. M.; Jamar, C.; Rochus, P.; Dere,
   K. P.; Howard, R. A.; Michels, D. J.; Freeland, S.; Lemen, J. R.;
   Stern, R. A.
1998SoPh..183..305N    Altcode:
  Solar EUV images recorded by the EUV Imaging Telescope (EIT) on SOHO
  have been used to evaluate temperature and density as a function of
  position in two largescale features in the corona observed in the
  temperature range of 1.0-2.0 MK. Such observations permit estimates
  of longitudinal temperature gradients (if present) in the corona and,
  consequently, estimates of thermal conduction and radiative losses
  as a function of position in the features. We examine two relatively
  cool features as recorded in EIT's Fe ix/x (171 Å) and Fe xii (195 Å)
  bands in a decaying active region. The first is a long-lived loop-like
  feature with one leg, ending in the active region, much more prominent
  than one or more distant footpoints assumed to be rooted in regions of
  weakly enhanced field. The other is a near-radial feature, observed
  at the West limb, which may be either the base of a very high loop
  or the base of a helmet streamer. We evaluate energy requirements to
  support a steady-state energy balance in these features and find in
  both instances that downward thermal conductive losses (at heights
  above the transition region) are inadequate to support local radiative
  losses, which are the predominant loss mechanism. The requirement that a
  coronal energy deposition rate proportional to the square of the ambient
  electron density (or pressure) is present in these cool coronal features
  provides an additional constraint on coronal heating mechanisms.

---------------------------------------------------------
Title: A new perspective on the sun from SOHO-challenges for atomic
    physics
Authors: Dere, Kenneth; Mason, Helen
1998AIPC..434..213D    Altcode: 1998amda.conf..213D
  The Solar and Heliospheric Observatory (SOHO) carries several
  ultraviolet spectrometers to diagnose the plasma conditions of
  the solar atmosphere in order to address several outstanding
  questions in solar research: why is the corona hot and how is the
  solar wind accelerated. Diagnostic techniques for determining the
  magnetohydrodynamic state (magnetic field, density, temperature,
  velocity) are discussed. We describe the CHIANTI database which has been
  designed to provide the necessary spectroscopic diagnostics for these
  data as well as for other spectroscopic missions. The database is built
  on 3 main files for each ion: atomic energy levels, radiative data,
  and electron collisional data. The electron collision strengths are
  assessed and scaled using the Burgess and Tully scaling laws. Analyses
  of EUV line intensities often reveal discrepancies between observed
  and predicted line intensities of about of 2 when considering lines of
  the same ion. A more recent analysis has shown that it is possible to
  arrive at a subset of EUV spectral lines where the line intensities
  are reproducible to within about 25%. For X-ray lines, as will be
  observed by AXAF, there is still considerable need for energy levels,
  radiative data and collision strengths, particularly for the Δn&gt;=1
  transitions.

---------------------------------------------------------
Title: LASCO/EIT Observations of Coronal Mass Ejections from
    Large-Scale Filament Channels
Authors: Plunkett, S. P.; Dere, K. P.; Howard, R. A.; Michels, D. J.;
   Brueckner, G. E.; Thompson, B. J.; Delaboudiniere, J. -P.
1998ASPC..150..475P    Altcode: 1998npsp.conf..475P; 1998IAUCo.167..475P
  No abstract at ADS

---------------------------------------------------------
Title: CHIANTI - an Atomic Database For Emission Lines Paper I:
    Wavelengths Greater than 50 Angstroms
Authors: Dere, K. P.; Landi, E.; Mason, H. E.; Fossi, B. C. M.; Young,
   P. R.
1998ASPC..143..390D    Altcode: 1998sigh.conf..390D
  No abstract at ADS

---------------------------------------------------------
Title: LASCO and EIT Observations of the Dynamic Corona
Authors: Dere, K. P.; Brueckner, G. E.
1998HiA....11..861D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Important atomic processes in solar physics
Authors: Dere, K.
1998sese.conf..283D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: White-Light Coronal Mass Ejections: A New Perspective from
    LASCO
Authors: St. Cyr, O. C.; Howard, R. A.; Simnett, G. M.; Gurman, J. B.;
   Plunkett, S. P.; Sheeley, N. R.; Schwenn, R.; Koomen, M. J.; Brueckner,
   G. E.; Michels, D. J.; Andrews, M.; Biesecker, D. A.; Cook, J.; Dere,
   K. P.; Duffin, R.; Einfalt, E.; Korendyke, C. M.; Lamy, P. L.; Lewis,
   D.; Llebaria, A.; Lyons, M.; Moses, J. D.; Moulton, N. E.; Newmark,
   J.; Paswaters, S. E.; Podlipnik, B.; Rich, N.; Schenk, K. M.; Socker,
   D. G.; Stezelberger, S. T.; Tappin, S. J.; Thompson, B.; Wang, D.
1997ESASP.415..103S    Altcode: 1997cpsh.conf..103S
  No abstract at ADS

---------------------------------------------------------
Title: The Structure of "halo" Coronal Mass Ejections
Authors: Vourlidas, A.; Howard, R. A.; Dere, K. P.; Passwaters, S. E.
1997AAS...191.7305V    Altcode: 1997BAAS...29.1321V
  We investigate the relation between the structure of "halo" coronal
  mass ejections (CMEs) and the global coronal structure. In particular,
  we compare two "halo" events which occured on October 21, 1997 and were
  observed with the SoHO/LASCO coronographs at a high cadence. Although
  the two CME occured at different locations on the solar disk, they
  both exhibit similar morphology which appear to be influenced by the
  global coronal structure. By comparing the data from the coronaraphs,
  EIT and magnetograms, we will attempt to decipher the interplay between
  the ejected material and the surrounding corona.

---------------------------------------------------------
Title: LASCO observations of CMEs with helical geometries
Authors: Dere, K.
1997AAS...19112005D    Altcode: 1997BAAS...29R1402D
  In the past, many observations of coronal mass ejections (CMEs) have
  been obtained. Nevertheless, their structure and magnetic topology
  remains an open question. Previous observations have often been found
  consistent with simple loop, arcade or bubble geometries. More recently,
  helical flux rope geometries have been suggested by Low, Chen, Rust and
  Kumar, and Wu et al. Observations of CMEs with the LASCO coronagraphs
  on SOHO include events which appear to be consistent with a toroidal
  geometry. This topology is also that deduced for magnetic clouds
  observed near the Earth. Examples of helical CMEs observed with LASCO
  are presented and analyzed.

---------------------------------------------------------
Title: Analysis of Coronal Mass Ejections observed by LASCO
Authors: Subramanian, P.; Dere, K. P.; Howard, R. A.; St. Cyr, C.;
   Brueckner, G. E.
1997AAS...191.7306S    Altcode: 1997BAAS...29.1321S
  The LASCO instrument on the SOHO spacecraft has been observing
  coronal mass ejections from the sun from February 1996 to the present
  time. This covers a range of solar activity ranging from near-minimum
  activity to increasing activity. We present a database of coronal mass
  ejection locations, times and velocities. These are then compared
  with photospheric magnetic field patterns and large scale coronal
  structures. We hope to gain an understanding of coronal mass ejection
  initiation mechanisms through these observations. Preliminary results
  from our analyses will be presented here.

---------------------------------------------------------
Title: LASCO Observations of Disconnected Magnetic Structures Out
    to Beyond 28 Solar Radii During Coronal Mass Ejections
Authors: Simnett, G. M.; Tappin, S. J.; Plunkett, S. P.; Bedford,
   D. K.; Eyles, C. J.; St. Cyr, O. C.; Howard, R. A.; Brueckner, G. E.;
   Michels, D. J.; Moses, J. D.; Socker, D.; Dere, K. P.; Korendyke,
   C. M.; Paswaters, S. E.; Wang, D.; Schwenn, R.; Lamy, P.; Llebaria,
   A.; Bout, M. V.
1997SoPh..175..685S    Altcode:
  Two coronal mass ejections have been well observed by the LASCO
  coronagraphs to move out into the interplanetary medium as disconnected
  plasmoids. The first, on July 28, 1996, left the Sun above the west
  limb around 18:00 UT. As it moved out, a bright V-shaped structure
  was visible in the C2 coronagraph which moved into the field-of-view
  of C3 and could be observed out to beyond 28 solar radii. The derived
  average velocity in the plane of the sky was 110 ± 5 km s<SUP>-1</SUP>
  out to 5 solar radii, and above 15 solar radii the velocity was 269
  ± 10 km s<SUP>-1</SUP>. Thus there is evidence of some acceleration
  around 6 solar radii. The second event occurred on November 5, 1996
  and left the west limb around 04:00 UT. The event had an average
  velocity in the plane of the sky of ∼54 km s<SUP>-1</SUP> below
  4 R⊙, and it accelerated rapidly around 5 R⊙ up to 310 ± 10 km
  s<SUP>-1</SUP>. In both events the rising plasmoid is connected back
  to the Sun by a straight, bright ray, which is probably a signature of
  a neutral sheet. In the November event there is evidence for multiple
  plasmoid ejections. The acceleration of the plasmoids around a projected
  altitude of 5 solar radii is probably a manifestation of the source
  surface of the solar wind.

---------------------------------------------------------
Title: First View of the Extended Green-Line Emission Corona At
    Solar Activity Minimum Using the Lasco-C1 Coronagraph on SOHO
Authors: Schwenn, R.; Inhester, B.; Plunkett, S. P.; Epple, A.;
   Podlipnik, B.; Bedford, D. K.; Eyles, C. J.; Simnett, G. M.; Tappin,
   S. J.; Bout, M. V.; Lamy, P. L.; Llebaria, A.; Brueckner, G. E.;
   Dere, K. P.; Howard, R. A.; Koomen, M. J.; Korendyke, C. M.; Michels,
   D. J.; Moses, J. D.; Moulton, N. E.; Paswaters, S. E.; Socker, D. G.;
   St. Cyr, O. C.; Wang, D.
1997SoPh..175..667S    Altcode:
  The newly developed C1 coronagraph as part of the Large-Angle
  Spectroscopic Coronagraph (LASCO) on board the SOHO spacecraft has
  been operating since January 29, 1996. We present observations
  obtained in the first three months of operation. The green-line
  emission corona can be made visible throughout the instrument's full
  field of view, i.e., from 1.1 R⊙ out to 3.2 R⊙ (measured from Sun
  center). Quantitative evaluations based on calibrations cannot yet be
  performed, but some basic signatures show up even now: (1) There are
  often bright and apparently closed loop systems centered at latitudes
  of 30° to 45° in both hemispheres. Their helmet-like extensions
  are bent towards the equatorial plane. Farther out, they merge into
  one large equatorial `streamer sheet' clearly discernible out to 32
  R⊙. (2) At mid latitudes a more diffuse pattern is usually visible,
  well separated from the high-latitude loops and with very pronounced
  variability. (3) All high-latitude structures remain stable on time
  scales of several days, and no signature of transient disruption of
  high-latitude streamers was observed in these early data. (4) Within
  the first 4 months of observation, only one single `fast' feature was
  observed moving outward at a speed of 70 km s<SUP>-1</SUP> close to
  the equator. Faster events may have escaped attention because of data
  gaps. (5) The centers of high-latitude loops are usually found at the
  positions of magnetic neutral lines in photospheric magnetograms. The
  large-scale streamer structure follows the magnetic pattern fairly
  precisely. Based on our observations we conclude that the shape
  and stability of the heliospheric current sheet at solar activity
  minimum are probably due to high-latitude streamers rather than to
  the near-equatorial activity belt.

---------------------------------------------------------
Title: EIT Observations of the Extreme Ultraviolet Sun
Authors: Moses, D.; Clette, F.; Delaboudinière, J. -P.; Artzner,
   G. E.; Bougnet, M.; Brunaud, J.; Carabetian, C.; Gabriel, A. H.;
   Hochedez, J. F.; Millier, F.; Song, X. Y.; Au, B.; Dere, K. P.; Howard,
   R. A.; Kreplin, R.; Michels, D. J.; Defise, J. M.; Jamar, C.; Rochus,
   P.; Chauvineau, J. P.; Marioge, J. P.; Catura, R. C.; Lemen, J. R.;
   Shing, L.; Stern, R. A.; Gurman, J. B.; Neupert, W. M.; Newmark,
   J.; Thompson, B.; Maucherat, A.; Portier-Fozzani, F.; Berghmans, D.;
   Cugnon, P.; Van Dessel, E. L.; Gabryl, J. R.
1997SoPh..175..571M    Altcode:
  The Extreme Ultraviolet Imaging Telescope (EIT) on board the SOHO
  spacecraft has been operational since 2 January 1996. EIT observes
  the Sun over a 45 x 45 arc min field of view in four emission line
  groups: Feix, x, Fexii, Fexv, and Heii. A post-launch determination
  of the instrument flatfield, the instrument scattering function, and
  the instrument aging were necessary for the reduction and analysis
  of the data. The observed structures and their evolution in each
  of the four EUV bandpasses are characteristic of the peak emission
  temperature of the line(s) chosen for that bandpass. Reports on the
  initial results of a variety of analysis projects demonstrate the range
  of investigations now underway: EIT provides new observations of the
  corona in the temperature range of 1 to 2 MK. Temperature studies of
  the large-scale coronal features extend previous coronagraph work
  with low-noise temperature maps. Temperatures of radial, extended,
  plume-like structures in both the polar coronal hole and in a low
  latitude decaying active region were found to be cooler than the
  surrounding material. Active region loops were investigated in detail
  and found to be isothermal for the low loops but hottest at the loop
  tops for the large loops.

---------------------------------------------------------
Title: CHIANTI - an atomic database for emission lines
Authors: Dere, K. P.; Landi, E.; Mason, H. E.; Monsignori Fossi,
   B. C.; Young, P. R.
1997A&AS..125..149D    Altcode:
  A comprehensive set of accurate atomic data is required for analyses of
  astrophysical and solar spectra. CHIANTI provides a database of atomic
  energy levels, wavelengths, radiative data and electron excitation
  data for ions which are abundant in cosmic plasmas. The most recent
  electron excitation data have been assessed and stored following
  the method of \cite[Burgess \&amp; Tully (1992)]{bur92}. The current
  version is essentially complete for specifying the emission spectrum
  at wavelengths greater than 50 Angstroms. A list of observed lines in
  the spectral region between 50 and 1100 Angstroms has been compiled
  and compared with the lines predicted by the CHIANTI database. The
  CHIANTI database reproduces the vast majority of lines observed at
  these wavelengths. CHIANTI includes IDL (Interactive Data Language)
  routines to calculate optically thin synthetic spectra for equilibrium
  conditions. IDL routines to calculate theoretical line intensities
  required for electron density or temperature diagnostics and emission
  measure studies are also included. The CHIANTI atomic database and
  supporting IDL routines are available by anonymous FTP.

---------------------------------------------------------
Title: The Relationship of Green-Line Transients to White-Light
    Coronal Mass Ejections
Authors: Plunkett, S. P.; Brueckner, G. E.; Dere, K. P.; Howard,
   R. A.; Koomen, M. J.; Korendyke, C. M.; Michels, D. J.; Moses, J. D.;
   Moulton, N. E.; Paswaters, S. E.; St. Cyr, O. C.; Socker, D. G.;
   Wang, D.; Simnett, G. M.; Bedford, D. K.; Biesecker, D. A.; Eyles,
   C. J.; Tappin, S. J.; Schwenn, R.; Lamy, P. L.; Llebaria, A.
1997SoPh..175..699P    Altcode:
  We report observations by the Large Angle Spectrometric Coronagraph
  (LASCO) on the SOHO spacecraft of three coronal green-line transients
  that could be clearly associated with coronal mass ejections (CMEs)
  detected in Thomson-scattered white light. Two of these events, with
  speeds &gt;25 km s<SUP>-1</SUP>, may be classified as `whip-like'
  transients. They are associated with the core of the white-light
  CMEs, identified with erupting prominence material, rather than with
  the leading edge of the CMEs. The third green-line transient has a
  markedly different appearance and is more gradual than the other two,
  with a projected outward speed &lt;10 km s<SUP>-1</SUP>. This event
  corresponds to the leading edge of a `streamer blowout' type of CME. A
  dark void is left behind in the emission-line corona following each of
  the fast eruptions. Both fast emission-line transients start off as a
  loop structure rising up from close to the solar surface. We suggest
  that the driving mechanism for these events may be the emergence of new
  bipolar magnetic regions on the surface of the Sun, which destabilize
  the ambient corona and cause an eruption. The possible relationship of
  these events to recent X-ray observations of CMEs is briefly discussed.

---------------------------------------------------------
Title: MHD Interpretation of LASCO Observations of a Coronal Mass
    Ejection as a Disconnected Magnetic Structure
Authors: Wu, S. T.; Guo, W. P.; Andrews, M. D.; Brueckner, G. E.;
   Howard, R. A.; Koomen, M. J.; Korendyke, C. M.; Michels, D. J.; Moses,
   J. D.; Socker, D. G.; Dere, K. P.; Lamy, P. L.; Llebaria, A.; Bout,
   M. V.; Schwenn, R.; Simnett, G. M.; Bedford, D. K.; Eyles, C. J.
1997SoPh..175..719W    Altcode:
  We present a qualitative and quantitative comparison of a single
  coronal mass ejection (CME) as observed by LASCO (July 28-29, 1996)
  with the results of a three-dimensional axisymmetric time-dependent
  magnetohydrodynamic model of a flux rope interacting with a helmet
  streamer. The particular CME considered was selected based on the
  appearance of a distinct `tear-drop' shape visible in animations
  generated from both the data and the model.

---------------------------------------------------------
Title: EIT and LASCO Observations of the Initiation of a Coronal
    Mass Ejection
Authors: Dere, K. P.; Brueckner, G. E.; Howard, R. A.; Koomen, M. J.;
   Korendyke, C. M.; Kreplin, R. W.; Michels, D. J.; Moses, J. D.;
   Moulton, N. E.; Socker, D. G.; St. Cyr, O. C.; Delaboudinière, J. P.;
   Artzner, G. E.; Brunaud, J.; Gabriel, A. H.; Hochedez, J. F.; Millier,
   F.; Song, X. Y.; Chauvineau, J. P.; Marioge, J. P.; Defise, J. M.;
   Jamar, C.; Rochus, P.; Catura, R. C.; Lemen, J. R.; Gurman, J. B.;
   Neupert, W.; Clette, F.; Cugnon, P.; Van Dessel, E. L.; Lamy, P. L.;
   Llebaria, A.; Schwenn, R.; Simnett, G. M.
1997SoPh..175..601D    Altcode:
  We present the first observations of the initiation of a coronal mass
  ejection (CME) seen on the disk of the Sun. Observations with the EIT
  experiment on SOHO show that the CME began in a small volume and was
  initially associated with slow motions of prominence material and a
  small brightening at one end of the prominence. Shortly afterward,
  the prominence was accelerated to about 100 km s<SUP>-1</SUP> and
  was preceded by a bright loop-like structure, which surrounded an
  emission void, that traveled out into the corona at a velocity of
  200-400 km s<SUP>-1</SUP>. These three components, the prominence,
  the dark void, and the bright loops are typical of CMEs when seen at
  distance in the corona and here are shown to be present at the earliest
  stages of the CME. The event was later observed to traverse the LASCO
  coronagraphs fields of view from 1.1 to 30 R⊙. Of particular interest
  is the fact that this large-scale event, spanning as much as 70 deg in
  latitude, originated in a volume with dimensions of roughly 35" (2.5
  x 10<SUP>4</SUP> km). Further, a disturbance that propagated across
  the disk and a chain of activity near the limb may also be associated
  with this event as well as a considerable degree of activity near the
  west limb.

---------------------------------------------------------
Title: Origin and Evolution of Coronal Streamer Structure During
    the 1996 Minimum Activity Phase
Authors: Wang, Y. -M.; Sheeley, N. R., Jr.; Howard, R. A.; Kraemer,
   J. R.; Rich, N. B.; Andrews, M. D.; Brueckner, G. E.; Dere, K. P.;
   Koomen, M. J.; Korendyke, C. M.; Michels, D. J.; Moses, J. D.;
   Paswaters, S. E.; Socker, D. G.; Wang, D.; Lamy, P. L.; Llebaria,
   A.; Vibert, D.; Schwenn, R.; Simnett, G. M.
1997ApJ...485..875W    Altcode:
  We employ coronal extrapolations of solar magnetograph data to interpret
  observations of the white-light streamer structure made with the LASCO
  coronagraph in 1996. The topological appearance of the streamer belt
  during the present minimum activity phase is well described by a model
  in which the Thomson-scattering electrons are concentrated around a
  single, warped current sheet encircling the Sun. Projection effects
  give rise to bright, jet-like structures or spikes whenever the current
  sheet is viewed edge-on multiple spikes are seen if the current sheet is
  sufficiently wavy. The extreme narrowness of these features in polarized
  images indicates that the scattering layer is at most a few degrees
  wide. We model the evolution of the streamer belt from 1996 April to
  1996 September and show that the effect of photospheric activity on
  the streamer belt topology depends not just on the strength of the
  erupted magnetic flux, but also on its longitudinal phase relative
  to the background field. Using flux transport simulations, we also
  demonstrate how the streamer belt would evolve during a prolonged
  absence of activity.

---------------------------------------------------------
Title: Nonthermal Velocities in the Solar Transition Zone and Corona
Authors: Doyle, J. G.; O'Shea, E.; Erdélyi, R.; Dere, K. P.; Socker,
   D. G.; Keenan, F. P.
1997SoPh..173..243D    Altcode:
  Nonthermal velocities are presented for spectral lines covering the
  temperature range 10 4-10 6 K, measured from high-spectral-resolution
  data for several solar features observed at the limb by the high
  resolution telescope and spectrograph (HRTS), including a coronal hole,
  `quiescent regions' and several small-scale active regions. These
  results are compared with predictions based on acoustic waves and
  heating via Alfvén waves. It is likely that more than one mechanism is
  operating simultaneously, in particular, resonant Alfvén wave heating,
  which is very sensitive to background plasma motions.

---------------------------------------------------------
Title: Measurements of Flow Speeds in the Corona Between 2 and 30
    R<SUB>⊙</SUB>
Authors: Sheeley, N. R.; Wang, Y. -M.; Hawley, S. H.; Brueckner,
   G. E.; Dere, K. P.; Howard, R. A.; Koomen, M. J.; Korendyke, C. M.;
   Michels, D. J.; Paswaters, S. E.; Socker, D. G.; St. Cyr, O. C.;
   Wang, D.; Lamy, P. L.; Llebaria, A.; Schwenn, R.; Simnett, G. M.;
   Plunkett, S.; Biesecker, D. A.
1997ApJ...484..472S    Altcode:
  Time-lapse sequences of white-light images, obtained during sunspot
  minimum conditions in 1996 by the Large Angle Spectrometric Coronagraph
  on the Solar and Heliospheric Observatory, give the impression of
  a continuous outflow of material in the streamer belt, as if we
  were observing Thomson scattering from inhomogeneities in the solar
  wind. Pursuing this idea, we have tracked the birth and outflow of
  50-100 of the most prominent moving coronal features and find that:
  <P />1. They originate about 3-4 R<SUB>⊙</SUB> from Sun center as
  radially elongated structures above the cusps of helmet streamers. Their
  initial sizes are about 1 R<SUB>⊙</SUB> in the radial direction and
  0.1 R<SUB>⊙</SUB> in the transverse direction. <P />2. They move
  radially outward, maintaining constant angular spans and increasing
  their lengths in rough accord with their speeds, which typically
  double from 150 km s<SUP>-1</SUP> near 5 R<SUB>⊙</SUB> to 300 km
  s<SUP>-1</SUP> near 25 R<SUB>⊙</SUB>. <P />3. Their individual speed
  profiles v(r) cluster around a nearly parabolic path characterized
  by a constant acceleration of about 4 m s<SUP>-2</SUP> through most
  of the 30 R<SUB>⊙</SUB> field of view. This profile is consistent
  with an isothermal solar wind expansion at a temperature of about
  1.1 MK and a sonic point near 5 R<SUB>⊙</SUB>. <P />Based on their
  relatively small initial sizes, low intensities, radial motions, slow
  but increasing speeds, and location in the streamer belt, we conclude
  that these moving features are passively tracing the outflow of the
  slow solar wind.

---------------------------------------------------------
Title: Association of Extreme-Ultraviolet Imaging Telescope (EIT)
    Polar Plumes with Mixed-Polarity Magnetic Network
Authors: Wang, Y. -M.; Sheeley, N. R.; Dere, K. P.; Duffin, R. T.;
   Howard, R. A.; Michels, D. J.; Moses, J. D.; Harvey, J. W.; Branston,
   D. D.; Delaboudinière, J. -P.; Artzner, G. E.; Hochedez, J. F.;
   Defise, J. M.; Catura, R. C.; Lemen, J. R.; Gurman, J. B.; Neupert,
   W. M.; Newmark, J.; Thompson, B.; Maucherat, A.; Clette, F.
1997ApJ...484L..75W    Altcode:
  SOHO EIT spectroheliograms showing the polar coronal holes during the
  present sunspot minimum are compared with National Solar Observatory
  (Kitt Peak) magnetograms taken in Fe I λ8688 and Ca II λ8542. The
  chromospheric λ8542 magnetograms, obtained on a routine, near-daily
  basis since 1996 June, reveal the Sun's strong polar fields with
  remarkable clarity. We find that the Fe IX λ171 polar plumes occur
  where minority-polarity flux is in contact with flux of the dominant
  polarity inside each polar hole. Moreover, the locations of “plume
  haze” coincide approximately with the patterns of brightened He
  II λ304 network within the coronal hole. The observations appear
  to be consistent with mechanisms of plume formation involving
  magnetic reconnection between unipolar flux concentrations and nearby
  bipoles. The fact that minority-polarity fields constitute only a small
  fraction of the total magnetic flux within the polar holes suggests
  that plumes are not the main source of the high-speed polar wind.

---------------------------------------------------------
Title: The Solar-B Mission
Authors: Antiochos, Spiro; Acton, Loren; Canfield, Richard; Davila,
   Joseph; Davis, John; Dere, Kenneth; Doschek, George; Golub, Leon;
   Harvey, John; Hathaway, David; Hudson, Hugh; Moore, Ronald; Lites,
   Bruce; Rust, David; Strong, Keith; Title, Alan
1997STIN...9721329A    Altcode:
  Solar-B, the next ISAS mission (with major NASA participation), is
  designed to address the fundamental question of how magnetic fields
  interact with plasma to produce solar variability. The mission has
  a number of unique capabilities that will enable it to answer the
  outstanding questions of solar magnetism. First, by escaping atmospheric
  seeing, it will deliver continuous observations of the solar surface
  with unprecedented spatial resolution. Second, Solar-B will deliver the
  first accurate measurements of all three components of the photospheric
  magnetic field. Solar-B will measure both the magnetic energy driving
  the photosphere and simultaneously its effects in the corona. Solar-B
  offers unique programmatic opportunities to NASA. It will continue an
  effective collaboration with our most reliable international partner. It
  will deliver images and data that will have strong public outreach
  potential. Finally, the science of Solar-B is clearly related to the
  themes of origins and plasma astrophysics, and contributes directly
  to the national space weather and global change programs.

---------------------------------------------------------
Title: Using LASCO Observations to Infer Solar Wind Flow Near the Sun
Authors: Sheeley, N. R., Jr.; Brueckner, G. E.; Dere, K. P.; Howard,
   R. A.; Korendyke, C. M.; Michels, D. J.; Socker, D. G.; Koomen, M. J.;
   Paswaters, S. E.; Wang, D.; Lamy, P. L.; Llebaria, A.; Schwenn, R.;
   St Cyr, O. C.; Simnett, G. M.; Plunkett, S.; Biesecker, D. A.
1997SPD....28.0301S    Altcode: 1997BAAS...29..907S
  We have continued to track individual coronal features as they become
  detached from helmet streamers and move outward from the Sun. The
  composite speed profile for 50-100 features has a parabolic shape
  with a constant acceleration of about 4 m/s(2) over the 2-30 R field
  of view. This well-determined speed profile contrasts strongly with
  the nearly uniform scatterplot obtained for about 50 nominal coronal
  mass ejections (CMEs), and suggests that these detached bits of coronal
  “debris” are passively tracing the speed of the slow solar wind. We
  have also begun the more difficult task of tracking outflow along
  polar plumes and will summarize these results as of June 1997.

---------------------------------------------------------
Title: EIT and LASCO observations of the initiation of a coronal
    mass ejection
Authors: Dere, K.; Brueckner, G. E.; Delaboudiniere, J. -P.
1997SPD....28.0502D    Altcode: 1997BAAS...29R.908D
  We present the first observations of the initiation of a coronal mass
  ejection (CME) seen on the disk of the Sun. Observations with the EIT
  experiment on SOHO show that the CME began in a small volume and was
  initially associated with slow motions of prominence material and a
  small brightening at one end of the prominence. Shortly afterward,
  the prominence was accelerated to about 200 kms and was preceded by
  a bright loop-like structure, which surrounded an emission void,
  that traveled out into the corona at a velocity of 400 kms. These
  three components, the prominence, the dark void, and the bright loops
  are typical of CMEs when seen at distance in the corona and here are
  shown to be present at the earliest stages of the CME. The event was
  later observed to traverse the LASCO coronagraphs fields of view from
  1.1 to 30 R_⊙. Of particular interest is the fact that this large
  scale event, spanning as much as 70 degrees in latitude, originated
  in a volume with dimensions of roughly 35" (2.5 x 10(4) km). Further,
  a disturbance that propagated across the disk and a chain of activity
  near the limb may also be associated with this event as well as a
  considerable degree of activity near the west limb.

---------------------------------------------------------
Title: Observations of Coronal Features by EIT above an Active Region
    by EIT and Implications for Coronal Heating
Authors: Neupert, W. M.; Newmark, J.; Thompson, B. J.; Catura, R.;
   Moses, J. D.; Portier-Fozzani, F.; Delaboudiniere, J. P.; Gabriel, A.;
   Artzner, G.; Clette, F.; Cugnon, P.; Maucherat, A.; Defise, J. M.;
   Jamar, C.; Rochus, P.; Howard, R.; Michels, D.; Dere, K.; Freeland,
   S.; Lemen, J.; Stern, R.; Gurman, J.
1997SPD....28.0115N    Altcode: 1997BAAS...29..881N
  The EUV Imaging Telescope (EIT) on the SOHO provides the capability
  for multi-wavelength imaging of the corona in four spectral bands,
  centered at 171, 195, 284, and 304 Angstroms, using multilayer telescope
  technology. These bands encompass coronal temperatures from 1 MK
  to 2.5 MK as well as the upper chromosphere, at about 60,000 K. In
  particular, nearly simultaneous imaging in the 171 and 195 Angstrom
  bands, the former including major Fe IX and Fe X emission lines, the
  latter including a strong Fe XII line, provides a capability to infer
  the morphology and characteristics of the corona at temperatures of
  1.0 - 1.7 MK. We have examined the corona in this temperature range
  over an active region observed from SOHO from May - September, 1996 and
  find that low-lying loops (below a density scale height of 75,000 km,
  characteristic of Fe X) vary little in brightness and temperature along
  their length. For features extending to greater heights, however, both
  brightness gradients and temperature gradients are observed. Preliminary
  analysis of the observations when the region was on the West limb
  on September 30 indicates a small positive temperature gradient of
  approximately 0.5 K/km in one loop system that extended above 100,000
  km. On the other hand, a nearly radial feature extending to the edge of
  the EIT FOV was isothermal or had at most a slight negative temperature
  gradient. Such measurements may have application to the modeling of
  coronal loops and streamers and the processes of coronal heating and
  solar wind acceleration.

---------------------------------------------------------
Title: VizieR Online Data Catalog: CHIANTI - An Atomic Database For
    Emission Lines I. (Dere+ 1997)
Authors: Dere, K. P.; Landi, E.; Mason, H. E.; Monsignori Fossi,
   B. C.; Young, P. R.
1997yCat..41250149D    Altcode:
  A comprehensive set of accurate atomic data is required for analyses of
  astrophysical and solar spectra. CHIANTI provides a database of atomic
  energy levels, wavelengths, radiative data and electron excitation
  data for ions which are abundant in cosmic plasmas. The most recent
  electron excitation data have been assessed and stored following
  the method of Burgess &amp; Tully (1992A&amp;A...254..436B). The
  current version is essentially complete for specifying the emission
  spectrum at wavelengths greater than 50Å. A list of observed lines
  in the spectral region between 50 and 1100Å has been compiled
  and compared with the lines predicted by the CHIANTI database. The
  CHIANTI database reproduces the vast majority of lines observed at
  these wavelengths. CHIANTI includes IDL (Interactive Data Language)
  routines to calculate optically thin synthetic spectra for equilibrium
  conditions. IDL routines to calculate theoretical line intensities
  required for electron density or temperature diagnostics and emission
  measure studies are also included. The CHIANTI atomic database and
  supporting IDL routines are available by anonymous FTP. (1 data file).

---------------------------------------------------------
Title: Imaging the solar corona in the EUV
Authors: Delaboudiniere, J. -P.; Stern, R. A.; Maucherat, A.;
   Portier-Fozzani, F.; Neupert, W. M.; Gurman, J. B.; Catura, R. C.;
   Lemen, J. R.; Shing, L.; Artzner, G. E.; Brunaud, J.; Gabriel, A. H.;
   Michels, D. J.; Moses, J. D.; Au, B.; Dere, K. P.; Howard, R. A.;
   Kreplin, R.; Defise, J. M.; Jamar, C.; Rochus, P.; Chauvineau, J. P.;
   Marioge, J. P.; Clette, F.; Cugnon, P.; van Dessel, E. L.
1997AdSpR..20.2231D    Altcode:
  The SOHO (SOlar and Heliospheric Observatory) satellite was launched on
  December 2nd 1995. After arriving at the Earth-Sun (L1) Lagrangian point
  on February 14th 1996, it began to continuously observe the Sun. As
  one of the instruments onboard SOHO, the EIT (Extreme ultraviolet
  Imaging Telescope) images the Sun's corona in 4 EUV wavelengths. The
  He II filter at 304 A˚ images the chromosphere and the base of the
  transition region at a temperature of 5 - 8 x 10^4 K; the Fe IX-X
  filter at 171 A˚ images the corona at a temperature of ~ 1.3 x 10^6 K;
  the Fe XII filter at 195 A˚ images the quiet corona outside coronal
  holes at a temperature of ~ 1.6 x 10^6 K; and the Fe XV filter at 284
  A˚ images active regions with a temperature of ~ 2.0 x 10^6 K. About
  5000 images have been obtained up to the present. In this paper,
  we describe also some aspects of the telescope and the detector
  performance for application in the observations. Images and movies
  of all the wavelengths allow a look at different phenomena present in
  the Sun's corona, and in particular, magnetic field reconnection.

---------------------------------------------------------
Title: Dynamical Evolution of a Coronal Mass Ejection (CME) to
Magnetic Cloud: A Preliminary Analysis of the January 6-10, 1997
    CME Observed by LASCO/SOHO
Authors: Wu, S. T.; Guo, W. P.; Michels, D. J.; Andrews, M. D.;
   Brueckner, G. E.; Howard, R. A.; Koomen, M. J.; Korendyke, C. M.;
   Moses, J. D.; Socker, D. G.; Dere, K. P.; Bougeret, Jean-Louis; Lamy,
   P. L.; Schwenn, R.; Simnett, G. M.
1997ESASP.404..739W    Altcode: 1997cswn.conf..739W
  No abstract at ADS

---------------------------------------------------------
Title: EIT and LASCO Observations of the Initiation of a Coronal
    Mass Ejection
Authors: Dere, K. P.; Brueckner, G. E.; Howard, R. A.; Koomen, M. J.;
   Korendyke, C. M.; Michels, D. J.; Moses, J. D.; Moulton, N. E.; Socker,
   D. G.; Delaboudiniere, J. P.; Hochedez, J. F.; Lamy, P. L.; Schwenn,
   R.; Simnett, G. M.; Defise, J. M.; Catura, R. C.
1997IAUJD..19E..18D    Altcode:
  We present the first observations of the initiation of a corona mass
  ejection (CME) seen on the disk of the Sun. Observations with the EIT
  and LASCO experiments on SOHO show that the CME starts in a small volume
  and is associated with slow motions of prominence material. At about
  the same time, a shock wave is created that travels out into the corona
  at a velocity of 400 km s^{-1} ahead of an eruptive prominence. This
  shock wave is clearly the event that is later seen as a classical CME
  when observed in the coronagraph above 1.5 solar radii. Although the
  CME clearly starts in a small region, a chain of activity near the
  limb may also be associated with this event.

---------------------------------------------------------
Title: First Results from EIT
Authors: Clette, F.; Delaboudiniere, J. -P.; Artzner, G. E.; Brunaud,
   J.; Gabriel, A. H.; Hochedez, J. -F.; Millier, F.; Song, X. Y.; Au, B.;
   Dere, K. P.; Howard, R. A.; Kreplin, R.; Michels, D. J.; Moses, J. D.;
   Defise, J. -M.; Jamar, C.; Rochus, P.; Chauvineau, J. -P.; Marioge,
   J. -P.; Catura, R. C.; Lemen, J. R.; Shing, L.; Stern, R. A.; Gurman,
   J. B.; Neupert, W. M.; Maucherat, A.; Cugnon, P.; van Dessel, E. L.
1997ASPC..118..268C    Altcode: 1997fasp.conf..268C
  The Extreme-UV Imaging telescope has already produced more than 15000
  wide-field images of the corona and transition region, on the disk
  and up to 1.5R_⊙ above the limb, with a pixel size of 2.6\arcsec. By
  using four different emission lines, it provides the global temperature
  distribution in the quiet corona, in the range 0.5 to 3*E(6) K. Its
  excellent sensitivity and wide dynamic range allow unprecedented views
  of low emission features, even inside coronal holes. Those so-called
  “quiet” regions actually display a wide range of dynamical phenomena,
  in particular at small spatial scales and at time scales going down
  to only a few seconds, as revealed by all EIT time sequences of
  full- or partial-field images. The initial results presented here
  demonstrate the importance of this wide-field imaging experiment for
  a good coordination between SOHO and ground-based solar telescopes,
  as well as for science planning.

---------------------------------------------------------
Title: The Rate of Magnetic Reconnection Observed in the Solar
    Atmosphere
Authors: Dere, Kenneth P.
1996ApJ...472..864D    Altcode:
  The structure of the solar corona is often observed to evolve in a
  manner that is generally attributed to the process of magnetic field
  line reconnection. The spatial and temporal scales for a variety of
  reconnection events have been examined on the basis of descriptions in
  the scientific literature. These events tend to fall into two general
  categories. In the first category, reconnection proceeds as the corona
  adjusts itself to the emergence of new magnetic flux. In the second
  category, the field lines have been explosively blown open by a flare or
  mass ejection, and the field lines eventually return to a more potential
  field configuration by means of reconnection. Estimates of the density,
  temperature, and magnetic field strength in the reconnection volume
  provide a basis on which to calculate the reconnection rate expected
  for resistive diffusion, tearing mode reconnection, and reconnection
  at the Alfvén speed. The observed temporal and spatial scales of the
  reconnection events indicate that the rate of reconnection is on the
  order of 0.001-0.1 of the Alfvén rate, the Alfvén speed divided by
  the observed length scale. This indicates that the effective Reynolds
  number for large-scale structures in the corona is of the order of 10-
  1000. In none of the cases examined does the reconnection appear to be
  driven by external flows, but the process is more properly described
  as the relaxation of nonpotential magnetic field configurations toward
  a potential configuration.

---------------------------------------------------------
Title: STEREO: a solar terrestrial event observer mission concept
Authors: Socker, Dennis G.; Antiochos, S. K.; Brueckner, Guenter E.;
   Cook, John W.; Dere, Kenneth P.; Howard, Russell A.; Karpen, J. T.;
   Klimchuk, J. A.; Korendyke, Clarence M.; Michels, Donald J.; Moses,
   J. Daniel; Prinz, Dianne K.; Sheely, N. R.; Wu, Shi T.; Buffington,
   Andrew; Jackson, Bernard V.; Labonte, Barry; Lamy, Philippe L.;
   Rosenbauer, H.; Schwenn, Rainer; Burlaga, L.; Davila, Joseph M.; Davis,
   John M.; Goldstein, Barry; Harris, H.; Liewer, Paulett C.; Neugebauer,
   Marcia; Hildner, E.; Pizzo, Victor J.; Moulton, Norman E.; Linker,
   J. A.; Mikic, Z.
1996SPIE.2804...50S    Altcode:
  A STEREO mission concept requiring only a single new spacecraft has been
  proposed. The mission would place the new spacecraft in a heliocentric
  orbit and well off the Sun- Earth line, where it can simultaneously view
  both the solar source of heliospheric disturbances and their propagation
  through the heliosphere all the way to the earth. Joint observations,
  utilizing the new spacecraft and existing solar spacecraft in earth
  orbit or L1 orbit would provide a stereographic data set. The new
  and unique aspect of this mission lies in the vantage point of the
  new spacecraft, which is far enough from Sun-Earth line to allow an
  entirely new way of studying the structure of the solar corona, the
  heliosphere and solar-terrestrial interactions. The mission science
  objectives have been selected to take maximum advantage of this new
  vantage point. They fall into two classes: those possible with the
  new spacecraft alone and those possible with joint measurements using
  the new and existing spacecraft. The instrument complement on the new
  spacecraft supporting the mission science objectives includes a soft
  x-ray imager, a coronagraph and a sun-earth imager. Telemetry rate
  appears to be the main performance determinant. The spacecraft could
  be launched with the new Med-Lite system.

---------------------------------------------------------
Title: Next-generation EUV imaging spectrometer for solar flare
    observations
Authors: Moses, J. Daniel; Brueckner, Guenter E.; Dere, Kenneth P.;
   Korendyke, Clarence M.; Moulton, Norman E.; Prinz, Dianne K.; Seely,
   John F.; Socker, Dennis G.; Bruner, Marilyn E.; Lemen, James R.
1996SPIE.2804..260M    Altcode:
  The Naval Research Laboratory Skylab SO82A slitless spectrograph
  provided solar flare observations that have never been equaled
  in diagnostic capabilities for interpreting thermal flare
  physics. Improvements in detector technology, optics and optical
  coating technology, and almost two decades of analysis of SO82A data
  can be combined with the basic concept of an EUV objective grating
  spectrograph to build an instrument to address many of the remaining
  mysteries of solar flares. This next generation instrument incorporates
  two sets of two identical, orthogonally mounted slitless spectrographic
  Cassegrain telescopes. Each telescope consists of a multilayer coated,
  Wadsworth mount objective grating and multilayer coated spherical
  secondary mirror; a backside illuminated CCD detector is installed
  at the focal plane. The orthogonal mounting changes the dispersion
  direction by 90 degrees on the disk image; processing on the two
  resulting images allows recovery of the undispersed disk image and
  spectral line profiles. The resulting instrument will obtain high time
  cadence, spectrally-dispersed images with improved spatial resolution,
  dynamic range, signal-to-noise ratio, and velocity discrimination.

---------------------------------------------------------
Title: A Model for Active Region Emission at Centimeter Wavelengths
Authors: Nindos, A.; Alissandrakis, C. E.; Gelfreikh, G. B.; Kundu,
   M. R.; Dere, K. P.; Korzhavin, A. N.; Bogod, V. M.
1996SoPh..166...55N    Altcode:
  We present multi-frequency observations and model computations of the
  microwave emission of a solar active region. The radio observations
  were obtained with the RATAN-600 at several wavelengths between 0.8
  and 31.6 cm and with the VLA at 6 and 20 cm. The active region was
  also observed in the EUV O Iv lines by the HRTS instrument aboard
  the Space Shuttle Spacelab-2 mission. These lines are formed in the
  chromosphere-corona transition region and their intensity ratio is
  sensitive to pressure. Photospheric magnetograms provided both the
  longitudinal and the transverse component of the magnetic field. The
  microwave observations were checked against model computations
  taking into account both the free-free and the gyro-resonance emission
  mechanisms and using the pressure data from the O IV lines. The magnetic
  field was computed through constant-α force-free extrapolations of
  the longitudinal photospheric field. We computed both the flux from
  2 to 20 cm and the spatial structure of the microwave emission at 6
  and 20 cm. The comparison of the computed and observed flux spectra
  allowed us to estimate the magnetic field strength at the base of the
  transition region and in the low corona, as well as the values of the
  conductive flux and the height of the base of the transition region. The
  model maps at 6 cm and 20 cm showed that α was not constant above the
  active region; the same conclusion was reached on the basis of the
  photospheric observations. The use of pressure measurements allowed
  us to identify microwave structures which were determined by pressure
  enhancements. At 6 cm the computations confirmed the fact that the
  magnetic field is the principal factor that determines the structure
  of sunspot-associated sources and showed that the effect of pressure
  variations was small. Pressure variations were more important at 20 cm,
  where the peak of the emission was associated with the sunspot and a
  diffuse component was associated with the plage which had an average
  pressure higher by a factor of 1.54 than the sunspot.

---------------------------------------------------------
Title: CHIANTI - an Atomic Database for Emission Line Spectroscopy:
    Version 1 - Wavelengths greater than 50 Angstroms
Authors: Dere, K. P.; Monsignori-Fossi, B. C.; Landi, E.; Mason,
   H. E.; Young, P. R.
1996AAS...188.8501D    Altcode: 1996BAAS...28..961D
  A comprehensive set of accurate atomic data is required for analyses of
  astrophysical and solar spectra. CHIANTI provides an atomic database of
  energy levels (wavelengths), radiative data and electron excitation data
  for ions which are abundant in astrophysical plasmas. The most recent
  electron excitation data have been assessed and stored following the
  method of Burgess and Tully (1992). CHIANTI includes IDL (Interactive
  Data Language) routines to produce optically thin synthetic spectra
  for lambda &gt; 50 Angstroms, assuming equilibrium conditions. It also
  includes IDL routines to calculate theoretical line intensities required
  for electron density or temperature diagnostics and emission measure
  studies. The CHIANTI atomic database and supporting IDL routines are
  available by anonymous FTP.

---------------------------------------------------------
Title: LASCO Observations of the 03Feb96 Streamer Blow-out
Authors: Andrews, M. D.; Korendyke, C. M.; Koomen, M. J.; Brueckner,
   G. E.; Cook, J. W.; Dere, K. P.; Howard, R. A.; Michels, D. J.; Moses,
   J. D.; Morrill, J. S.; Moulton, N. E.; Paswaters, S. E.; Socker, D. G.;
   St. Cyr, O. C. St.; Wang, D.; Lamy, P. L.; Llebaria, A.; Bout, M. V.;
   Schwenn, R.; Podlipnik, B.; Bedford, D. K.; Biesecker, D. A.; Eyles,
   C. J.; Plunkett, S.; Simnett, G. M.
1996AAS...188.3716A    Altcode: 1996BAAS...28..880A
  The C2 and C3 telescopes on the Large Angle Spectrometric Coronograph
  (LASCO) have recorded images of a Streamer Blow-out which occured
  on 03Feb96. We will present a series of images produces by combining
  data from the 2 coronographs. These images show a rapid evolution of
  the coronal streamer belt over projected distances of 2 to 20 solar
  radii. The streamer belt shows a dramatic brightening, which is seen to
  propagate outward. A bubble-like structure is seen to move away from
  the Sun and expand. At the end of this event, the equatorial corona
  is significantly less bright than prior to the event.

---------------------------------------------------------
Title: LASCO Observations of the Solar Corona to 32 R<SUB>sun</SUB>
Authors: Cook, J. W.; Koomen, M. J.; Korendyke, C. M.; Brueckner,
   G. E.; Dere, K. P.; Howard, R. A.; Michels, D. J.; Morrill, J. S.;
   Moses, J. D.; Socker, D. G.; Paswaters, S. E.; Wang, D.; Moulton,
   N. E.; Cyr, O. C. St.; Andrews, M. D.; Schwenn, R.; Podlipnik, B.;
   Lamy, P. L.; Llebaria, A.; Bout, M. V.; Simnett, G. M.; Bedford,
   D. K.; Eyles, C. J.; Plunkett, S.; Biesecker, D. A.
1996AAS...188.3717C    Altcode: 1996BAAS...28..880C
  The Large Angle Spectrometric Coronagraph (LASCO) was launched on
  board the SOHO satellite on 2 December 1995. The C3 externally-occulted
  coronagraph of LASCO observes the solar corona over a field from 3.7-32
  R_ ⊙, using a 1024x1024 CCD detector with a pixel size corresponding
  to 56 arc sec. Observations can be made using color filters ranging
  from the blue (420-520 nm) to the near-IR (860-1050 nm), and through
  polarizing filters. We report on early observations of the solar corona
  out to 32 R<SUB>sun</SUB>.

---------------------------------------------------------
Title: Preliminary Photometric Calibration of LASCO C3 Coronagraph
    Images using Pre-Flight Laboratory Images of Standard Sources and
    In-Flight Images of Standard Stars
Authors: Korendyke, C. M.; Koomen, M. J.; Andrews, M. D.; Brueckner,
   G. E.; Cook, J. W.; Dere, K. P.; Howard, R. A.; Michels, D. J.;
   Moses, J. D.; Morrill, J. S.; Moulton, N. E.; Paswaters, S. E.;
   Socker, D. G.; St. Cyr, O. C.; Wang, D.; Lamy, P. L.; Llebaria, A.;
   Bout, M. V.; Schwenn, R.; Podlipnik, B.; Bedford, D. K.; Biesecker,
   D. A.; Eyles, C. J.; Plunkett, S.; Simnett, G. M.
1996AAS...188.3621K    Altcode: 1996BAAS...28..876K
  The C3 coronagraph is a wide field (+/-8.0 degrees), externally
  occulted, white light coronagraph. The instrument is one of three
  coronagraphs comprising the Large Angle Spectrometric COronagraph
  (LASCO) experiment mounted on the Solar Heliospheric Observatory
  satellite. The satellite was launched on Dec. 2, 1996; C3 observations
  began in early Jan. 1997. The coronagraph optical train includes a set
  of five broadband color filters mounted in a wheel. Prior to flight,
  an image was obtained through each color filter of a well characterized,
  rear-illuminated, opal glass diffusing screen. The C3 in-flight images,
  in addition to the coronal structures, also contain several hundred
  bright stars. We present a comparison of the photometric calibration
  derived from standard stars with the laboratory measurements. The
  resulting calibration is then used to examine color variations in the
  white light corona over the field of view. The LASCO experiment was
  developed by a scientific consortium of members from NRL (USA), MPAe
  (Germany), LAS (France) and U. Birmingham (United Kingdom).

---------------------------------------------------------
Title: Observations of the South coronal hole from EIT and YOHKOH
Authors: Handy, B. N.; Catura, R.; Freeland, S.; Lemen, J.; Stern,
   R.; Gurman, J. B.; Delaboudiniere, J. P.; Artzner, G.; Gabriel, A.;
   Maucherat, A.; Defise, J. M.; Jamar, C.; Rochus, P.; Clette, F.;
   Cugnon, P.; Howard, R.; Michels, D.; Moses, J. D.; Dere, K.; Cyr,
   O. C. St.; Catura, R.; Freeland, S.; Lemen, J.; Stern, R.; Neupert,
   W.; Einfalt, E.; Newmark, J.
1996AAS...188.0206H    Altcode: 1996BAAS...28..821H
  The Extreme ultraviolet Imaging Telescope (EIT) on board the
  SOHO spacecraft is capable of studying solar transition region,
  chomospheric and coronal plasmas over bandpasses optimized for He II
  304 Angstroms (0.08 MK), Fe IX/X 171, 173 Angstroms (0.8 - 1.0 MK),
  Fe XII 195 Angstroms (1.5 MK), and Fe XV 284 Angstroms (2.0 - 2.5
  MK) with 2.5 arcsecond spatial resolution. This telescope in concert
  with the Yohkoh/SXT instrument allows us to simultaneously observe
  solar structures at temperatures ranging from less than 0.1MK in the
  transition region to over 3MK in the solar corona. EIT has had several
  opportunities to observe the South coronal hole with high spatial and
  temporal resolution. We compare observations from EIT and SXT with
  an eye towards correlating temporal variations over the range of
  wavelengths, activity of polar crown filament systems and relating
  large-scale morphology of the X-ray corona to the transition region
  in He II.

---------------------------------------------------------
Title: There's No Such Thing as the Quiet Sun: EUV Movies from SOHO
Authors: Gurman, J. B.; Delaboudiniere, J. P.; Artzner, G.; Gabriel,
   A.; Maucherat, A.; Defise, J. M.; Jamar, C.; Rochus, P.; Clette, F.;
   Cugnon, P.; Howard, R.; Michels, D.; Moses, J. D.; Dere, K.; Cyr,
   O. C. St.; Catura, R.; Freeland, S.; Lemen, J.; Stern, R.; Neupert,
   W.; Einfalt, E.; Newmark, J.
1996AAS...188.3718G    Altcode: 1996BAAS...28..880G
  We present unique time series of high-resolution solar images from the
  normal-incidence Extreme ultraviolet Imaging Telescope (EIT) on board
  the SOHO spacecraft. With a pixel scale of 2.6 arc sec and a detector
  dynamic range of &gt; 10(4) , the EIT can be used to study the dynamics
  of chromospheric and coronal features in multilayer bandpasses optimized
  for He II 304 Angstroms (0.08 MK), Fe IX/X 171, 173 Angstroms (0.8 -
  1.0 MK), Fe XII 195 Angstroms (1.5 MK), and Fe XV 284 Angstroms (2.0 -
  2.5 MK). Among the most striking features of the digital movies we will
  display are: the dynamic nature of small-scale loop features in the
  polar coronal holes, the constant activity of the polar crown filament
  systems, the locations of the bases of polar plumes, the presence
  of dark (scattering) filament material in the coronal emission line
  images, and the evolution of a unique, linear, dark feature in a young
  active region. The latter feature is suggestive of the “coronal void”
  observed in the electron scattering corona by Macqueen et al./ (1983).

---------------------------------------------------------
Title: Coronal structure and heating: comparison between SXT/Yohkoh
    observations of an active region and magnetogram
Authors: Cheng, C. -C.; Dere, K. P.; Wu, S. T.; Hagyard, M. J.;
   Hiei, E.
1996AdSpR..17d.205C    Altcode: 1996AdSpR..17..205C
  We have studied the magnetic structure in AR 7150 (S09E06) observed on
  29 April 1992 by the Soft X-Ray Telescope (SXT) on Yohkoh. The observed
  X-ray images are compared with force-free magnetic fields with different
  values of alpha, extrapolated from the MSFC photospheric magnetogram
  observed at the same time. The results show that the magnetic field
  of the active region is not potential. Different groups of loops are
  characterized by different values of alpha. Bright loops correspond to
  field with large alpha, indicating twisting of the loop. However, there
  is no obvious correlation between the brightness of individual loops
  with the amount of twist. Further investigation of the magnetic state of
  the loop structure requires accurate nonlinear force-free calculations.

---------------------------------------------------------
Title: Observations of the south coronal hole from EIT and Yohkoh.
Authors: Handy, B. N.; Catura, R.; Freeland, S.; Lemen, J.; Stern,
   R.; Gurman, J. B.; Delaboudinière, J. P.; Artzner, G.; Gabriel,
   A.; Maucherat, A.; Defise, J. M.; Jamar, C.; Rochus, P.; Clette, F.;
   Cugnon, P.; Howard, R.; Michels, D.; Moses, J. D.; Dere, K.; St. Cyr,
   O. C.; Neupert, W.; Einfalt, E.; Newmark, J.
1996BAAS...28Q.821H    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Nonthermal velocities in the solar transition and coronal
    region observed with the high-resolution telescope and spectrograph
Authors: O'Shea, E.; Doyle, J. G.; Dere, K. P.; Keenan, F. P.
1996ASPC..109..145O    Altcode: 1996csss....9..145O
  No abstract at ADS

---------------------------------------------------------
Title: Observations of the comet Hyakutake by the LASCO coronagraph
    on the SOHO satellite.
Authors: Andrews, M. D.; Paswaters, S. E.; Brueckner, G. E.; Korendyke,
   C. M.; Dere, K. P.; Howard, R. A.; Michels, D. J.; Moses, J. D.;
   Morril, J. S.; Moulton, N. E.; Socker, D. G.; St. Cyr, O. C.; Wang,
   D.; Lamy, P. L.; Llebaria, A.; Bout, M. V.; Schwenn, R.; Podlipnik,
   B.; Bedford, D. K.; Biesecker, D. A.; Eyles, C. J.; Plunket, S.;
   Simnet, G. M.
1996BAAS...28.1195A    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: EIT: Extreme-Ultraviolet Imaging Telescope for the SOHO Mission
Authors: Delaboudinière, J. -P.; Artzner, G. E.; Brunaud, J.; Gabriel,
   A. H.; Hochedez, J. F.; Millier, F.; Song, X. Y.; Au, B.; Dere, K. P.;
   Howard, R. A.; Kreplin, R.; Michels, D. J.; Moses, J. D.; Defise,
   J. M.; Jamar, C.; Rochus, P.; Chauvineau, J. P.; Marioge, J. P.;
   Catura, R. C.; Lemen, J. R.; Shing, L.; Stern, R. A.; Gurman, J. B.;
   Neupert, W. M.; Maucherat, A.; Clette, F.; Cugnon, P.; Van Dessel,
   E. L.
1995SoPh..162..291D    Altcode:
  The Extreme-ultraviolet Imaging Telescope (EIT) will provide wide-field
  images of the corona and transition region on the solar disc and up to
  1.5 R⊙ above the solar limb. Its normal incidence multilayer-coated
  optics will select spectral emission lines from Fe IX (171 å), Fe
  XII (195 å), Fe XV (284 å), and He II (304 å) to provide sensitive
  temperature diagnostics in the range from 6 × 10<SUP>4</SUP> K to 3
  × 10<SUP>6</SUP> K. The telescope has a 45 x 45 arcmin field of view
  and 2.6 arcsec pixels which will provide approximately 5-arcsec spatial
  resolution. The EIT will probe the coronal plasma on a global scale,
  as well as the underlying cooler and turbulent atmosphere, providing
  the basis for comparative analyses with observations from both the
  ground and other SOHO instruments. This paper presents details of the
  EIT instrumentation, its performance and operating modes.

---------------------------------------------------------
Title: The Large Angle Spectroscopic Coronagraph (LASCO)
Authors: Brueckner, G. E.; Howard, R. A.; Koomen, M. J.; Korendyke,
   C. M.; Michels, D. J.; Moses, J. D.; Socker, D. G.; Dere, K. P.;
   Lamy, P. L.; Llebaria, A.; Bout, M. V.; Schwenn, R.; Simnett, G. M.;
   Bedford, D. K.; Eyles, C. J.
1995SoPh..162..357B    Altcode:
  The Large Angle Spectroscopic Coronagraph (LASCO) is a three
  coronagraph package which has been jointly developed for the Solar
  and Heliospheric Observatory (SOHO) mission by the Naval Research
  Laboratory (USA), the Laboratoire d'Astronomie Spatiale (France),
  the Max-Planck-Institut für Aeronomie (Germany), and the University
  of Birmingham (UK). LASCO comprises three coronagraphs, C1, C2, and C3,
  that together image the solar corona from 1.1 to 30 R<SUB>⊙</SUB> (C1:
  1.1 - 3 R<SUB>⊙</SUB>, C2: 1.5 - 6 R<SUB>⊙</SUB>, and C3: 3.7 - 30
  R<SUB>⊙</SUB>). The C1 coronagraph is a newly developed mirror version
  of the classic internally-occulted Lyot coronagraph, while the C2 and
  C3 coronagraphs are externally occulted instruments. High-resolution
  imaging spectroscopy of the corona from 1.1 to 3 R<SUB>⊙</SUB> can
  be performed with the Fabry-Perot interferometer in C1. High-volume
  memories and a high-speed microprocessor enable extensive on-board image
  processing. Image compression by a factor of about 10 will result in
  the transmission of 10 full images per hour.

---------------------------------------------------------
Title: Ultraviolet Observations of the Structure and Dynamics of an
    Active Region at the Limb
Authors: Korendyke, C. M.; Dere, K. P.; Socker, D. G.; Brueckner,
   G. E.; Schmieder, B.
1995ApJ...443..869K    Altcode:
  The structure and dynamics of active region NOAA 7260 at the limb have
  been studied using ultraviolet spectra and spectroheliograms obtained
  during the eighth rocket flight of the Naval Research Laboratory's
  High Resolution Telescope an Spectrograph (HRTS). The instrument
  configuration included a narrow-bandpass spectroheliograph to observe
  the Sun in the lines of C IV lambda 550 and a tandem-Wadsworth mount
  spectrograph to record the profiles of chromospheric transition
  region and coronal lines in the 1850-2670 A region. The combination
  of high spatial resolution and high spectral purity C IV slit jaw
  images with ultraviolet emission-line spectra corresponding allows
  examination of a variety of active region phenomena. A time series
  of spectroheliograms shows large-scale loop systems composed of
  fine-scale threads with some extending up to 100 Mm above the
  limb. The proper motion of several supersonic features, including
  a surge were measured. The accelerated plasmas appear in several
  different geometries and environments. Spectrograph exposures were
  taken with the slit positioned at a range of altitudes above the limb
  and provide a direct comparison between coronal, transition region
  and chromospheric emission line profiles. The spectral profiles of
  chromospheric and transition region emission lines show line-of-sight
  velocities up to 70 km/s. These lower temperature, emission-line spectra
  show small-scale spatial and velocity variations which are correlated
  with the threadlike structures seen in C IV. Coronal lines of Fe XII
  show much lower velocities and no fine structure.

---------------------------------------------------------
Title: The Rate of Magnetic Reconnection in the Solar Corona
Authors: Dere, K. P.
1995SPD....26..612D    Altcode: 1995BAAS...27..963D
  No abstract at ADS

---------------------------------------------------------
Title: EIT: The Extreme Ultraviolet Imaging Telescope. Synoptic
    Observations of Small and Large-Scale Coronal Structures
Authors: Clette, F.; Delaboudinière, J. P.; Dere, K. P.; Cugnon,
   P.; EIT Science Team
1995LNP...444..251C    Altcode: 1995cmer.conf..251C
  The EIT will provide wide-field images of the corona and transition
  region, on the solar disc and up to 1 R<SUB>⊙</SUB> above the
  limb. Its normal incidence multilayer-coated optics will select the
  spectral emission lines of four ions (Fe IX, 171 Å; Fe XII, 195
  Å; Fe XV, 284 Å; Hell, 304 Å), providing a sensitive temperature
  diagnostic in the range 6.10<SUP>4</SUP> to 3.10<SUP>6</SUP>K. This
  SOHO instrument will thus probe the coronal plasma on a global scale,
  as well as the underlying cooler and turbulent atmosphere. The EIT's
  characteristics and performances are presented, and prospects for
  coordinated observations with ground-based radio observatories are
  outlined.

---------------------------------------------------------
Title: Magnetic Structure and Heating of an Active Region: Comparison
    Between SXT/Yohkoh Observations and Magnetogram
Authors: Cheng, C. -C.; Dere, K. P.; Wang, Jingxiu; Ai, Guoxiang
1994AAS...185.8604C    Altcode: 1994BAAS...26.1464C
  We have studied the magnetic structure of AR7420 observed on 9
  February 1993 by the Soft X-Ray Telescope (SXT) on Yohkoh. The
  observed X-ray images of the active region are compared with various
  force-free magnetic fields, extrapolated from the photospheric
  magnetograms obtained at the same time by the Huairou Station of the
  Beijing Astronomical Observatory. The results show that the magnetic
  configuration of the active region is not a potential field. Different
  groups of loops are characterized by different values of alpha ,
  indicating that the loops are twisted and that there are currents
  flowing through them. Here alpha is given by nabla times B=alpha B
  for a force free field, where B is the magnetic field. In particular,
  we find that there are opposite current systems in the active region,
  as specified by positive and negative values of alpha . In addition,
  we find that there is no obvious correlation between the brightness of
  individual loops with the amount of twist. Implications of the results
  will be discussed.

---------------------------------------------------------
Title: Hierarchy of spatial scale sin UV prominences
Authors: Schmieder, B.; Wiik, J. E.; Dere, K. P.
1994SSRv...70..175S    Altcode:
  Ultraviolet spectra of a quiescent prominence observed with theHigh
  Resolution Telescope and Spectrograph (HRTS) are analyzed. Different
  techniques lead to greatly different spatial scales for the prominence
  structures. The UV spectra show strong variations in intensity and
  Doppler shift on scales larger than 1700 km. Spectroscopic diagnostics
  employing line intensity ratios indicate the existence of scales
  between 400 m to some hundred kilometers. We attempt to interpret
  various aspects of the prominence intensities and velocities with a
  multiple thread model.

---------------------------------------------------------
Title: Solar mass flow in fine-scale structures
Authors: Dere, K. P.
1994SSRv...70...21D    Altcode:
  Observations of transient and steady velocities at chromospheric,
  transition region and coronal temperatures in the quiet Sun and coronal
  holes are reviewed. The relevance of fine-scale structures in governing
  the mass balance of the solar atmosphere is stressed. At present,
  a coherent picture of these mass flows does not exist. However, the
  current observational base of transition region and coronal velocity
  information is limited but should greatly improve with measurements
  from the SOHO satellite.

---------------------------------------------------------
Title: Solar Fine-Scale Structures in the Corona, Transition Region,
    and Lower Atmosphere
Authors: Moses, Dan; Cook, J. W.; Bartoe, J. -D. F.; Brueckner, G. E.;
   Dere, K. P.; Webb, D. F.; Davis, J. M.; Harvey, J. W.; Recely, F.;
   Martin, S. F.; Zirin, H.
1994ApJ...430..913M    Altcode:
  The American Science and Engineering Soft X-ray Imaging Payload and the
  Naval Research Laboratory High Resolution Telescope and Spectrograph
  (HRTS) were launched from White Sands on 1987 December 11 in coordinated
  sounding rocket flights. The goal was to investigate the correspondence
  of fine-scale structures from different temperature regimes in the
  solar atmosphere, and particularly the relationship between X-ray bright
  points (XBPs) and transition region explosive events. We present results
  of the analysis of co-aligned X-ray images, maps of sites of transition
  region explosive events observed in C IV 10<SUP>5</SUP>, HRTS 1600
  A spectroheliograms of the T<SUB>min</SUB> region, and ground-based
  magnetogram and He I 10830 A images. We examined the relationship
  of He I 10830 A dark features and evolving magnetic features which
  correspond to XBPs. We note a frequent double ribbon pattern of the
  He I dark feature counterparts to XBPs. We discuss an analysis of the
  relationship of XBPs to evolving magnetic features by Webb et al.,
  which shows that converging magnetic features of opposite polarity are
  the most significant magnetic field counterparts to XBPs. The magnetic
  bipolar features associated with XBPs appear as prominent network
  elements in chromospheric and transition region images. The features
  in C IV observations corresponding to XBP sites are in general bright,
  larger scale (approximately 10 arcsec) regions of complex velocity
  fields of order 40 km/s, which is typical of brighter C IV network
  elements. These C IV features do not reach the approximately 100 km/s
  velocities seen in the C IV explosive events. Also, there are many
  similar C IV bright network features without a corresponding XBP in the
  X-ray image. The transition region explosive events do not correspond
  directly to XBPs. The explosive events appear to be concentrated in
  the quiet Sun at the edges of strong network, or within weaker field
  strength network regions. We find a greater number of C IV events than
  expected from the results of a previous Spacelab 2 HRTS disk survey. We
  attribute this at least partly to better spatial resolution with the
  newer HRTS data. The full-disk X-ray image shows a pattern of dark
  lanes in quiet Sun areas. The number density of C IV events is twice
  as large inside as outside a dark lane (4.6 x 10<SUP>-3</SUP> vs. 2.3
  x 10<SUP>-3</SUP> explosive events per arcsec <SUP>2</SUP>). The dark
  lane corresponds to an old decaying magnetic neutral line. We suggest
  that this provides an increased opportunity for small-scale convergence
  and reconnection of opposite polarity magnetic field features, in
  analogy with the results of Webb et al. for XBPs but at a reduced
  scale of reconnection.

---------------------------------------------------------
Title: HRTS Observations of Explosive Events in a Flaring Active
    Region
Authors: Dere, K. P.; Martin, S. F.
1994kofu.symp..289D    Altcode:
  Explosive events are a highly dynamic, small-scale phenomena that are
  commonly observed on the Sun with the NRL High Resolution Telescope and
  Spectrograph (HRTS). There is now considerable evidence which suggests
  that they are signatures of magnetic reconnection during flux emergence
  and cancellation. Data from the Big Bear Solar Observatory and the
  HRTS instrument are used to demonstrate the direct correspondence
  between explosive events and evolving magnetic structures.

---------------------------------------------------------
Title: Combined HRTS-8 Sounding Rocket Observations and YOHKOH Soft
    X-ray Observations of NOAA Active Region 7260 at the Solar Limb
Authors: Korendyke, C. M.; Dere, K. P.; Brueckner, G. E.; Waljeski,
   K.; Lemen, J. R.
1994kofu.symp..293K    Altcode:
  On 24 August 1992, the Naval Research Laboratory (NRL) High Resolution
  Telescope and Spectrograph (HRTS) was launched aboard a Black Brant
  sounding rocket from White Sands, New Mexico. During the flight, the
  instrument recorded a unique set of near ultraviolet slit spectra and
  1550 A spectroheliograms of an active region at the solar limb. An
  extensive set of observations of this region were obtained with the
  Yohkoh Soft X-ray Telescope (SXT) near the time of the flight. The C IV
  spectroheliograms obtained during this flight are some of the highest
  resolution images of the solar transition region ever obtained. The
  spectra and spectroheliograms dramatically demonstrate the fundamental
  difference between coronal and chromospheric/transition-region plasmas
  at 700 km spatial scales. The cooler plasmas exhibit a great deal of
  dynamic, fine scale structure with significant flows or proper motion
  particularly in the transition zone loops. The coronal emission lines
  in the spectra! are relatively uniform and quiescent. The Yohkoh data
  during the period before and after the flight show a set of diffuse
  high temperature coronal loops with only minimal correspondence to
  the structures visible in the C IV spectroheliograms.

---------------------------------------------------------
Title: The Composition of a Coronal Active Region
Authors: Waljeski, K.; Moses, D.; Dere, K. P.; Saba, J. L. R.; Strong,
   K. T.; Webb, D. F.; Zarro, D. M.
1994ApJ...429..909W    Altcode:
  The relative abundances of iron, oxygen, magnesium, and neon in a
  coronal active region are determined from measurements of soft X-ray
  line and broadband intensities. The emission measure, temperature,
  and column density are derived from these measured intensities and are
  used to place a constraint on the abundances of the heavier elements
  relative to hydrogen in the corona. The intensity measurements were
  made on 1987 December 11, when an active region was observed jointly by
  the American Science and Engineering (AS&amp;E) High Resolution Soft
  X-Ray Imaging Sounding-Rocket Payload and the X-Ray Polychromator
  Flat Crystal Spectrometer (FCS) onboard the Solar Maximum Mission
  spacecraft. The coordinated observations include images through two
  broadband filters (8 to 29 A and 8 to 39, 44 to 60 A) and profiles
  of six emission lines: Fe XVII (15.01 A), FE VIII (15.26 A), O VIII
  (18.97 A), Mg XI (9.17 A), Ne IX (13.44 A), and Fe XVIII (14.21 A). The
  effects of resonance scattering are considered in the interpretation
  of the FCS line intensities. We calculated the expected intensity
  ratio of the two Fe XVII lines as a function of optical depth and
  compared this ratio with the observed intensity ratio to obtain the
  optical depths of each of the lines and the column density. The line
  intensities and the broadband filtered images are consistent with
  the emission from a thermal plasma where Fe, O, Mg, and Ne have
  the 'adopted coronal' abundances of Meyer (1985b) relative to one
  another, but are not consistent with the emission from a plasma having
  photospheric abundances: The ratios of the abundances of the low first
  ionization potential (FIP) elements (Fe and Mg) to the abundances of
  the high-FIP elements (Ne and O) are higher than the ratios seen in the
  photosphere by a factor of about 3.5. This conclusion is independent of
  the assumption of either an isothermal or a multithermal plasma. The
  column densities derived from the Fe XVII line ratio and the geometry
  of the active region provide a diagnostic of the abundance of hydrogen
  relative to the heavier elements. We find that the abundance of iron
  with respect to hydrogen in the corona is higher than the value given
  Meyer (1985b) by a factor of 8.2(-5.4, +5.1). This means that, for the
  observed active region, the absolute abundances of the low-FIP elements
  (Fe and Mg) are enhanced in the corona relative to the photosphere,
  while the abundances of the high-FIP elements (Ne and O) are either
  slightly enhanced in the corona or nearly the same in the photosphere
  and the corona.

---------------------------------------------------------
Title: Explosive events, magnetic reconnection, and coronal heating
Authors: Dere, K. P.
1994AdSpR..14d..13D    Altcode: 1994AdSpR..14...13D
  Signatures of explosive events are prominent in transition region
  spectra where they display exceptionally large velocities (&gt;100 km
  s<SUP>-1</SUP>) in small areas (1500 km). Their physical properties,
  deduced from previous analyses of HRTS spectra and more recent work, are
  summarized here. It now appears that the explosive events are associated
  with the process of magnetic cancellation and HRTS data obtained during
  the most recent rocket flight in 1990 provide direct evidence for this
  assertion. Flux cancellation, which tends to proceed on time-scales
  of hours, most likely involves magnetic reconnection in a very bursty
  manner which explains the small, short-lived explosive events. These
  reconnection events are part of a larger pattern where small flux
  elements emerge in the supergranule centers and are transported to
  the boundaries to continually regenerate the network fields on a
  timescale of about 8 hours. These timescales are also sufficiently
  short to account for the energetics of the quiet sun.

---------------------------------------------------------
Title: Observational characteristics of explosive events
Authors: Hénoux, J. -C.; Dere, K. P.
1994LNP...432..203H    Altcode:
  The characteristics of dynamic phenomena observed in the EUV with
  the HRTS instruments, chromospheric jets and explosive events, are
  reviewed here. Most of the review is devoted to explosive events that
  are short duration explosions involving a plasma at 105 K. These
  events are characterised by strong Doppler shifts rather than by
  brightness enhancements, contrary to EUV impulsive brightenings
  observed by SMM. They are presumably due to magnetic reconnection
  involving unresolved fine structures of the magnetic field near the
  network. The role of the density of concentrated magnetic fluxtubes
  in a reconnection scenario has still to be understood.

---------------------------------------------------------
Title: Observational characteristics of explosive events.
Authors: Hénoux, J. C.; Dere, K. P.
1994LNP...432..205H    Altcode: 1994LNPM...11..205H
  The characteristics of dynamic phenomena observed in the EUV with
  the HRTS instruments, chromospheric jets and explosive events, are
  reviewed. Most of the review is devoted to explosive events that are
  short duration explosions involving a plasma at 10<SUP>5</SUP>K. These
  events are characterised by strong Doppler shifts rather than by
  brightness enhancements, contrary to EUV impulsive brightenings
  observed by SMM. They are presumably due to magnetic reconnection
  involving unresolved fine structures of the magnetic field near the
  network. The role of the density of concentrated magnetic fluxtubes
  in a reconnection scenario has still to be understood.

---------------------------------------------------------
Title: A New Synthetic XUV Spectrum
Authors: Dere, K. P.; Mason, H. E.; Fossi, B. C. Monsignori; Waljeski,
   K. H.
1993AAS...18311203D    Altcode: 1993BAAS...25.1459D
  We have begun a program to develop a synthetic XUV spectrum for the
  70 - 2500 /AA wavelength region based on a critical analysis of the
  most recent calculations of atomic parameters, in particular, atomic
  collision strengths and their thermal averages. Ultraviolet spectra
  returned by the EUVE and HST instruments demonstrate a continued need
  for the most accurate atomic parameters in order to determine the
  physical conditions in the emitting plasmas. Most previous synthetic
  spectra has relied heavily on the gaunt factor approximation which can
  predict excitation rates only for dipole transitions and only to within
  a factor of 2 to 3. In many cases, direct calculations of the collision
  strengths are now available. Burgess and Tully (1992) have developed
  a technique for critically evaluating collision strength calculations
  and scaling and compacting the data. Different scalings are available
  for resonance, intercombination and forbidden excitations. This method
  will be applied in the construction of our spectrum. In the end, we
  intend to produce a set of critically evaluated atomic parameters
  from which the nearly optically thin spectrum of a low density
  astrophysical plasma can be calculated, together with the programs
  necessary to perform these calculations. We will include the ability
  to prescribe elemental abundances and to correct for optical depth
  and populations of metastable levels as a function of density. The
  data sets and programs will be made available by anonymous ftp.

---------------------------------------------------------
Title: A Description of the HRTS-8 Instrument Configuration
Authors: Korendyke, C. M.; Dere, K. P.; Brueckner, G. E.; Socker, D. G.
1993BAAS...25.1182K    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: HRTS Untraviolet Observations of the Chromosphere Transition
    Region and Corona of a Solar Active Region
Authors: Dere, K. P.; Korendyke, C. M.; Brueckner, G. E.
1993BAAS...25.1182D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: UV prominences observed with the HRTS: structure and physical
    properties
Authors: Wiik, J. E.; Dere, K.; Schmieder, B.
1993A&A...273..267W    Altcode:
  Ultraviolet spectra of two quiescent prominences (PL1, PL2) observed
  with the High Resolution Telescope and Spectrograph (HRTS) are described
  and analyzed. Meudon synoptic maps and spectroheliograms indicate that
  prominence PL 1 was extremely active during the flight and that material
  ejections were likely. PL2 appeared to be a more stable prominence. The
  significant differences between the spectra of the two prominences
  can perhaps be explained by their levels of activity. The spectrum of
  the more active prominence PL1 is dominated by transition zone lines
  formed near 10<SUP>5</SUP> K whereas the second prominence PL2 shows
  considerable emission of cooler chromospheric lines formed near 2
  × 1O<SUP>4</SUP> K. PL 1 also exhibits larger bulk flow velocities
  (up to ∼ 30 km s<SUP>-1</SUP>) and non-thermal velocities (∼20km
  s<SUP>-1</SUP>). From line ratios (O IV, N V, N IV, Si IV) a relatively
  large electron density (∼10<SUP>11</SUP> cm<SUP>-3</SUP>) is derived
  for the PL1 prominence transition region (PTR). In comparison, PL2 is
  a relatively quiet prominence with bulk flow velocities generally less
  than ∼3 km s<SUP>-1</SUP>. <P />Different techniques yield greatly
  different spatial scales for the prominence. The UV spectra show strong
  variations in intensity and Doppler shift on scales of about 1700km. The
  combined density and emission measures indicate path lengths of 400 m
  or less. The optical depth in C IV requires path lengths of 40 km or
  less. If, as suggested by these analyses, it is assumed that prominence
  emission is due to a number of micro-structures with a Gaussian velocity
  distribution, then spatial scales of the micro-structures of a few
  hundred kilometers are found.

---------------------------------------------------------
Title: Transition Region Explosive Events in an X-Ray Dark Lane
    Region of the Quiet Sun
Authors: Cook, J. W.; Moses, D.; Brueckner, G. E.; Dere, K. P.;
   Bartoe, J. -D. F.; Webb, D.; Davis, J. M.; Harvey, J. W.; Recely,
   F.; Martin, S. F.; Zirin, H.
1993BAAS...25.1181C    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Scaling Laws for Coronal Heating: X-ray Loop Observations
Authors: Waljeski, K.; Dere, K. P.; Moses, D.
1993BAAS...25.1212W    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Nonthermal Velocities in the Solar Transition Zone Observed
    with the High-Resolution Telescope and Spectrograph
Authors: Dere, K. P.; Mason, H. E.
1993SoPh..144..217D    Altcode:
  Data obtained during the first rocket flight of the NRL High Resolution
  Telescope and Spectrograph (HRTS) have been used to study nonthermal
  velocities for spectral lines primarily covering the temperature
  range 10<SUP>4</SUP> to 2 × 10<SUP>6</SUP> K. The high spectral and
  spatial resolution, combined with an enhanced dynamic intensity range
  of the reduced data, has enabled us to study the distribution of the
  nonthermal velocities for quiet and active regions. Average values
  of the nonthermal velocities peak at about 27 km s<SUP>−1</SUP>
  at 10<SUP>5</SUP> K for the quiet regions, with a wide distribution
  of nonthermal velocities for each line. The active region nonthermal
  velocities have a narrower distribution which is weighted towards higher
  values. The SiIV and C IV line profiles are not well described by a
  single Gaussian, indicating that high-velocity components (above 30 km
  s<SUP>−1</SUP>) are present in the quiet-Sun spectra. The radiative
  losses for all plasma above l0<SUP>5</SUP> K have been calculated for
  the quiet Sun, an active region and a coronal hole. These have been
  compared with the acoustic wave flux inferred from the nonthermal line
  widths. There appears to be a sufficient flux of waves to heat these
  regions of the atmosphere.

---------------------------------------------------------
Title: Observational test of coronal heating models.
Authors: Waljeski, Katrina; Dere, Ken P.; Moses, Dan
1992ESASP.348..281W    Altcode: 1992cscl.work..281W
  The properties of coronal loops are measured and used to test the
  predictions of coronal heating models. The coronal loop temperature,
  emission measure, geometry, and magnetic field strength are measured
  from broadband soft X-ray images obtained by the American Science
  and Engineering High Resolution Soft X-Ray Imaging Sounding Rocket
  Payload and from coordinated ground-based observations. The radiative
  energy loss rates for these loops, calculated from the observed plasma
  properties, are compared to the scalings with loop length or magnetic
  field strength predicted by various models of coronal heating. The
  loop scaling laws of Rosner, Tucker, and Vaiana and of Golub et al. are
  also tested with these observations.

---------------------------------------------------------
Title: Solar corona synoptic observations from SOHO with an Extreme
    Ultraviolet Imaging Telescope.
Authors: Delaboudinière, J. P.; Gabriel, A. H.; Artzner, G. E.;
   Dere, K.; Howard, R.; Michels, D.; Catura, R.; Lemen, J.; Stern, R.;
   Gurman, J.; Neupert, W.; Cugnon, P.; Koeckelenbergh, A.; van Dessel,
   E. L.; Jamar, C.; Maucherat, A.
1992ESASP.348...21D    Altcode: 1992cscl.work...21D
  The major scientific objective of the EUV Imaging Telescope (EIT)
  is to study the evolution of coronal structure over a wide range
  of spatial and temporal scales and temperatures. A second strategic
  objective is to provide full disk synoptic maps of the global corona
  to aid in unifying SOHO (Solar and Heliospheric Observatory)/Cluster
  investigations. EIT will also provide images to support the planning
  of detailed spectroscopic investigations by the CDS (Coronal Diagnostic
  Spectrometer) and SUMER spectrometers in SOHO. EIT observations will be
  made in four narrow spectral bands, centered at 171 A (Fe 9), 195 A(Fe
  12), 284 A (Fe 15), and 304 A (He 2) representing restricted temperature
  domains within a wide temperature range from 40,000 to 3,000,000
  K. The results will be images of the solar atmosphere from the upper
  chromosphere and transition region to the active region corona. These
  maps, made at appropriate time intervals, will be used to study the fine
  structures in the solar corona and to relate their dynamic properties
  to the underlying chromosphere and photosphere. Dynamic events in the
  inner corona will be related to white light transients in the outer
  corona, and observations of the internal structure of coronal holes
  will be used to investigate origins of the solar wind.

---------------------------------------------------------
Title: Intensity, velocity and turbulence in prominences observed
    with the HRTS instrument.
Authors: Schmieder, B.; Wiik, J. E.; Dere, K. P.
1992JAF....43...36S    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Explosive events and magnetic reconnection in the solar
    atmosphere
Authors: Dere, K. P.
1992AIPC..267...63D    Altcode: 1992ecsa.work...63D
  Explosive events are highly-dynamic, small-scale phenomena commonly
  observed in spectra of transition zone lines. Their velocities are near
  100 km s-1, sizes near 1500 km, and time scales near 60 s. They occur at
  a height of 1000-2000 km, below typical transition zone structures. It
  has been demonstrated that some explosive events are caused by
  emerging magnetic flux and there is good evidence to indicate that
  the great majority are related to magnetic flux cancellation. The most
  probable mechanism for their generation is magnetic reconnection. The
  characteristics of explosive events and flux cancellation taken together
  show that magnetic reconnection in the quiet sun apparently proceeds
  readily in rapid bursts along the neutral line separating opposite
  flux elements that are convected together by photospheric flows.

---------------------------------------------------------
Title: Ultraviolet Explosive Events and Evolving Magnetic Fields
Authors: Dere, K. P.; Martin, S. F.
1992AAS...180.5604D    Altcode: 1992BAAS...24..821D
  No abstract at ADS

---------------------------------------------------------
Title: Intensity, velocity and turbulence in prominences observed
    with the HRTS.
Authors: Wiik, J. E.; Dere, K.; Schmieder, B.
1992ESASP.344...65W    Altcode: 1992spai.rept...65W
  The moments of UV emission line profiles between 1206 and 1670 A
  observed in two quiescent prominences with the High Resolution Telescope
  and Spectrograph (HRTS) are analysed. Spectral lines in this region
  of the solar spectrum provide information on plasmas in the 10000K
  to 200000K range. In both prominences a good correlation is found
  between the intensities of lines formed at different temperatures. A
  good correlation is also found between the non-thermal velocities of
  different lines.

---------------------------------------------------------
Title: LASCO - Large Angle Spectrometric Coronagraph for SOHO
Authors: Howard, R. A.; Brueckner, G. E.; Dere, K. P.; Korendyke,
   C. M.; Koomen, M. J.; Michels, D. J.; Moses, D.; Socker, D. G.;
   Schwenn, R.; Inhester, B.; Lamy, P.; Maucherat, A.; Simnett, G. M.;
   Eyles, C.
1992AAS...180.3307H    Altcode: 1992BAAS...24..781H
  No abstract at ADS

---------------------------------------------------------
Title: Transition region dynamics.
Authors: Dere, K. P.
1992ESASP.344...43D    Altcode: 1992spai.rept...43D
  The solar transition region has qualities that make it an ideal testing
  ground for theories of coronal heating and dynamics. Strong diagnostic
  lines formed at transition region temperatures (2×10<SUP>5</SUP> to
  10<SUP>6</SUP>K) are found at VUV wavelengths that are observable with
  relatively straightforward optical techniques. The transition region
  is highly dynamic; nonthermal velocities peak at 10<SUP>5</SUP>K and
  high velocity explosive events, indicators of magnetic reconnection,
  are commonly found throughout the quiet and active sun. The fine-scale
  density and velocity structures indicate that important information
  will be found at spatial scales below 1″

---------------------------------------------------------
Title: Dynamics in the Prominence - Corona Transition Region from
    HRTS Spectra
Authors: Schmieder, B.; Dere, K. P.; Wiik, J. E.
1992LNP...399..333S    Altcode: 1992esf..coll..333S; 1992IAUCo.133..333S
  Line profiles of UV emission lines between 1206Å and 1670Å observed
  in two prominences with the High Resolution Telescope and Spectrograph
  (HRTS) are analysed. Spectral lines in this region of the solar spectrum
  such as C I, Fe II, Si IV and C IV, provide information on plasmas in
  the 10 000 K to 200 000 K range. In the active prominence observed
  with HRTS-1 a good correlation is found between the intensities and
  velocities of different lines formed over a range of temperatures. On
  the contrary, poor cross correlation between the velocities observed
  in plasmas of cold temperatures indicates the presence of different
  structures in the SL2 prominence. Microturbulent velocities from 0 to
  25km s-1 are found in both prominences.

---------------------------------------------------------
Title: The chromospheric and transition region manifestations of an
    Ellerman bomb.
Authors: Cook, J. W.; Brueckner, G. E.; Dere, K. P.; Martin, S. F.;
   Gayley, K. G.
1992BAAS...24.1074C    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Explosive events and magnetic reconnection in the solar
    atmosphere
Authors: Dere, K. P.
1992sws..coll...11D    Altcode:
  Signatures of explosive events are prominent in transition region
  spectra where they display large (100 km/s) in small areas (1500
  km). Their physical properties, deduced from previous analyses of
  HRTS spectra and more recent work, are summarized here. It now appears
  that the explosive events are associated with the process of magnetic
  cancellation and HRTS data obtained during the most recent rocket flight
  in 1990 provide direct evidence for this assertion. Flux cancellation,
  which tends to proceed with timescales of hours, most likely involved
  magnetic reconnection in a very bursty manner which explains the small,
  short-lived explosive events.

---------------------------------------------------------
Title: Relative Abundances in the Lower Solar Transition Region
Authors: Doschek, G. A.; Dere, K. P.; Lund, P. A.
1991ApJ...381..583D    Altcode:
  Properties of the lower solar transition region as determined from
  UV spectral lines recorded by the Naval Research Laboratory HRTS
  are investigated. The spectra were obtained from a rocket flight in
  July 1975. Variations of intensity ratios of strong lines of C IV,
  Si IV, C II, Si III, and O IV over the entire field of view of the
  HRTS instrument, which extends from disk center to the solar limb are
  discussed. The largest apparent abundance variations appear to be in
  the active regions surrounding a sunspot. The C/Si ratio is lower in
  the active regions than anywhere else in the instrument field of view,
  implying a lower C/Si abundance ratio in the active regions. There
  is a possible correlation of line intensity variation in the active
  region with Doppler shift of the lines; the explanation for this is
  unclear. The magnitude and reality of intensity ratio variations of
  all observed solar features are discussed, and monotonic center-to-limb
  intensity ratio variations due to the opacity of some of the spectral
  lines are measured.

---------------------------------------------------------
Title: Velocity Gradients in the Chromosphere-Corona Transition Region
Authors: Athay, R. G.; Dere, K. P.
1991ApJ...381..323A    Altcode:
  Velocity data obtained from Doppler shifts of EUV spectral lines
  observed with the High Resolution Telescope and Spectrograph flown
  on Spacelab II are analyzed to determine the properties of the mean
  velocities V-bar and its spatial variance V(sigma), for chromospheric
  and transition region lines. The lines studied include the ions O I,
  C I, Fe II, C II, Si III, Si IV, and C IV. The constancy of V(sigma)
  from center to limb together with a systematic maximum redshift in
  V-bar in central disk regions is interpreted to mean that the plasma
  flow is divergent from the tops of closed field lines and that the
  cool plasma more or less fills the magnetic loops from which most of
  the radiation originates. The same is true of the hotter plasma. It
  is suggested that the crossfield component of Delta T is large and
  that the alternation from cool loops to hot loops occurs on spatial
  scales much less than 1 arcsec.

---------------------------------------------------------
Title: Chromospheric and Transition Region Diagnostics Using
    Emission-Line Intensities
Authors: Athay, R. G.; Dere, K. P.
1991ApJ...379..776A    Altcode:
  EUV emission-line intensities from the HRTS experiment on Spacelab 2 are
  analyzed to determine the causes of intensity variations from point to
  point on the solar surface. Chromospheric lines of O I and transition
  region lines of C II, Si IV, and C IV exhibit saturation effects that
  limit the line intensities in the brighter regions. No such effect
  is found in lines of C I, Fe II, or Si III. The chromospheric lines
  saturate because the optical thickness exceeds the thermalization depth,
  whereas the transition region lines saturate because of the geometry
  of the unresolved fine structure. The latter is assumed to consist
  of elongated cylinder-like features oriented along magnetic lines of
  force that are mainly vertical. Saturation occurs when the optical
  thickness along the axis of the cylinders exceeds unity. Estimates
  based on the observed saturation effects give fill factors for the fine
  structure 0.005 and 0.4 at 100,000 K and 30,000 K, respectively. The
  corresponding lengths of the cylinders are estimated at 1000 km and
  40 km at the two temperatures.

---------------------------------------------------------
Title: Explosive events and magnetic reconnection in the solar
    atmosphere
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.; Ewing,
   J.; Lund, P.
1991JGR....96.9399D    Altcode:
  Explosive events are highly energetic, small-scale phenomena which are
  frequently detected throughout the quiet and active Sun. They are seen
  in profiles of spectral lines formed at transition zone temperatures
  as exceptionally Doppler-shifted features, typically at 100 km
  s<SUP>-1</SUP> to the red and/or blue of the rest wavelength. Sufficient
  observational evidence has now been developed to demonstrate that some
  explosive events are associated with the emergence of new magnetic
  flux. In these cases it is likely that the acceleration of plasma is
  caused by the magnetic reconnection resulting from flux emergence. We
  take as a working hypothesis the proposal that all explosive events
  are the result of magnetic reconnection. Since explosive events tend
  to occur on the edges of high photospheric magnetic field regions,
  we identify them with reconnection that occurs during the cancellation
  of photospheric magnetic flux (Martin, 1984; Livi et al., 1985). The
  combined observational characteristics of photospheric flux cancellation
  and transition zone explosive events provide powerful diagnostic
  information concerning the nature of magnetic reconnection. Reconnection
  in the quiet solar atmosphere apparently proceeds in bursts at sites
  much smaller than the boundary between opposite polarity flux elements
  that are observed to cancel in magnetograph sequences. Equating the
  velocity of the expelled transition zone plasma with the Alfvén speed
  yields magnetic field strengths of 20 G at the site of reconnection. The
  speed at which the reconnection proceeds is commensurate with the rapid
  rates predicted by Petschek (1964). ©1991 American Geophysical Union

---------------------------------------------------------
Title: The Magnetic Network Location of Explosive Events Observed
    in the Solar Transition Region
Authors: Porter, J. G.; Dere, K. P.
1991ApJ...370..775P    Altcode:
  Compact short-lived explosive events have been observed in solar
  transition region lines with the High-Resolution Telescope and
  Spectrograph (HRTS) flown by the Naval Research Laboratory on a series
  of rockets and on Spacelab 2. Data from Spacelab 2 are coaligned
  with a simultaneous magnetogram and near-simultaneous He I 10,380 -A
  spectroheliogram obtained at the National Solar Observatory at Kitt
  Peak. The comparison shows that the explosive events occur in the solar
  magnetic network lanes at the boundaries of supergranular convective
  cells. However, the events occur away from the larger concentrations
  of magnetic flux in the network, in contradiction to the observed
  tendency of the more energetic solar phenomena to be associated with
  the stronger magnetic fields.

---------------------------------------------------------
Title: The Prime Energy Release of a Solar Flare
Authors: Brueckner, G. E.; Moses, D.; Cook, J. W.; Dere, K. P.;
   Korendyke, C. M.; Socker, D. G.; Bartoe, J. -D. F.
1991BAAS...23.1026B    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Nonthermal Velocities in the Solar Transition Region
Authors: Dere, K. P.; Mason, H. E.
1991BAAS...23Q1028D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Flaring Active Region Structures in the Corona, Transition
    Region, and Lower Atmosphere Observed in the SAROC
Authors: Moses, D.; Brueckner, G. E.; Cook, J. W.; Dere, K. P.;
   Korendyke, C. M.; Socker, D. G.; Bartoe, J. -D. F.
1991BAAS...23.1026M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Coordinated observations with high resolution spectrographs
    (HRTS, SERTS, MSDP)
Authors: Schmieder, B.; Thompson, W. T.; Neupert, W. M.; Thomas,
   R. J.; Dere, K. P.
1991AdSpR..11e.255S    Altcode: 1991AdSpR..11R.255S
  Observations with the High Resolution Telescope Spectrograph
  (HRTS) aboard Spacelab2 in 1985, and more recently with the Solar
  Extreme-ultraviolet Rocket Telescope and Spectrometer (SERTS) during
  the rocket flight of May 5, 1989 were well coordinated with the Meudon
  instruments, principally with the Multichannel Subtractive Double Pass
  (MSDP) spectrograph. These instruments allow the study of phenomena
  in a large temperature range and the determination of the energy
  budget. MSDP observations coordinated with the SERTS have permitted
  the analysis of physical parameters of coronal plasma surrounding
  dynamical chromospheric events, such as preflaring region and a
  filament. By combining Hα spectrograms and HRTS data, C IV flow
  (~50 km s<SUP>-1</SUP>) detected at the footpoints of a prominence
  has been interpreted by horizontal velocities along the axis of the
  arches of the prominence.

---------------------------------------------------------
Title: High resolution solar physics from rockets
Authors: Dere, K. P.
1991AdSpR..11e.191D    Altcode: 1991AdSpR..11..191D
  Explosive events are highly energetic phenomena that are frequently
  seen throughout the quiet and active sun, particularly in spectral
  lines formed at transition zone temperatures. Sufficient observational
  evidence has now been developed to conclusively demonstrate that some
  explosive events are caused by magnetic reconnection in emerging
  magnetic flux regions. It is also consistent with observations of
  photospheric magnetic flux cancellation to propose that all explosive
  events are the result of magnetic reconnection. By combining the
  observational facts concerning photospheric flux cancellation and
  transition zone explosive events it can be shown that reconnection in
  the quiet solar atmosphere proceeds in bursts at sites much smaller
  than the boundary between opposite polarity flux elements that are
  observed to cancel in magnetograph sequences.

---------------------------------------------------------
Title: Bifurcation in the Low Chromosphere
Authors: Athay, R. Grant; Dere, K. P.
1990ApJ...358..710A    Altcode:
  Bright chromospheric faculae of diameter d(c) covering an area of
  the solar disk f(c) smaller than 1 yield a predictable level of limb
  brightening. For a resolution diameter d(r), the combination of f(c) and
  d(c) leads, also, to a prediction of the fraction, phi(0), of observing
  pixels (resolution areas) that are free of facular emission. Data from
  the first flight of the High Resolution Telescope and Spectrograph of
  the U.S. Naval Research Laboratory with d(r) about 1 arcsec are used to
  measure both the level of limb brightening and phi(0) in EUV emission
  lines of O I, C I, and Fe II. The results favor f(c) about 0.9 and d(c)
  greater than about 2.5 arcssec. It is concluded that the chromospheric
  temperature rise is present over about 90 percent of the solar surface.

---------------------------------------------------------
Title: Flow patterns in a sunspot region observed in the photosphere,
    chromosphere and transition region
Authors: Dere, K. P.; Schmieder, B.; Alissandrakis, C. E.
1990A&A...233..207D    Altcode:
  The flow patterns around a sunspot at photospheric, chromospheric, and
  transition zone temperatures is examined. The spiral fibril pattern
  observed in H-alpha is consistent with a constant alpha force-free
  field extrapolation of the photospheric magnetic field. Evidence
  is found for the first time that C IV fibrils near spots follow the
  field lines parallel to the chromospheric H-alpha fibrils. The observed
  large-scale pattern of redshifts and blueshifts in the vicinity of the
  sunspot is stable and conforms to the typical Evershed flow patterns
  of radial outflow at the photospheric levels and radial inflows at
  the chromospheric and transition region levels. The three-dimensional
  velocity vectors associated with this flow are derived assuming an
  axially symmetric Evershed flow.

---------------------------------------------------------
Title: The High Resolution Telescope and Spectrograph (HRTS) on
    Board the Orbiting Solar Laboratory (OSL)
Authors: Brueckner, G. E.; Bartoe, J. -D. F.; Dere, K. P.; Socker,
   D. G.
1990BAAS...22..845B    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Coronal Dark Lanes and the Location of Transition Region
    Explosive Events
Authors: Moses, D.; Cook, J. W.; Bartoe, J. -D. F.; Brueckner, G. E.;
   Dere, K. P.; Davis, J. M.
1990BAAS...22..899M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The HRTS/OSL Vacuum Ultraviolet CCD Development Program
Authors: Socker, D. G.; Dere, K. P.; Korendyke, C. M.
1990BAAS...22..889S    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Ultraviolet Spectra of a Prominence
Authors: Dere, K.; Lund, P.; Schmieder, B.
1990BAAS...22R.815D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Relationship between a spot and a filament observed during
    spacelab 2 mission
Authors: Schmieder, B.; Dere, K. P.; Raadu, M. A.; Démoulin, P.;
   Alissandrakis, C. E.
1990AdSpR..10i.195S    Altcode: 1990AdSpR..10..195S
  During the Spacelab 2 Mission, an active region including a sunspot,
  plages, fibrils and a filament which disappears during the observation
  period, was observed in Hα and in the C IV lines. The analysis of the
  observations leads to several conclusions. Shear in the active region
  filament is observed before its disappearance. Hα and C IV upflows
  in the filament are well correlated spatially, but the transition
  zone (C IV) velocities are an order of magnitude larger than the Hα
  chromospheric ones. Over the sunspot, the reverse-Evershed effect is
  observed in Hα and in C IV Dopplershift images while strong downflows
  are also detected in the C IV profiles. <P />Magnetograph data for
  the whole region are used to calculate the linear force-free magnetic
  field. A single value of the force-free parameter α is found to give a
  good fit to both the sheared filament structure and the sunspot spiral
  structures, indicating a causal relationship. <P />We propose a model
  based on the inductive coupling between current systems associated with
  the filament and the sunspot. Relaxation phenomena due to resistive
  effects in the filament could lead to irreversible conversion of
  magnetic energy into kinetic energy and heating.

---------------------------------------------------------
Title: Heating of the solar transition region in fine-scale structures
Authors: Dere, K. P.
1990AdSpR..10i.169D    Altcode: 1990AdSpR..10..169D
  Studies of the solar transition region with ultraviolet instruments
  such as the NRL High Resolution Telescope and Spectrograph (HRTS)
  point out the advantages of this region to understanding nonthermal
  heating in the solar atmosphere. In contrast to the classical picture
  where the transition zone is a thin region maintained simply by the
  dissipation of heat conducted down from the corona, high resolution
  spectroheliograms show that the transition zone consists of elongated
  structures that must be heated locally because the field aligned
  temperature gradients are insufficient to support the necessary
  conductive flux. An analysis of the observationally determined
  emission measures (n<SUB>e</SUB><SUP>2</SUP>Δ1) and pressures of
  transition region structures reveals that they consist of fine-scale
  subresolution structures with dimensions less than 100 km. Further
  evidence for subresolution structure is found in spectral line widths
  which are wider than expected from thermal broadening. The velocity
  power spectrum, derived from both resolved motions evident in net
  Doppler shifts of line profiles and unresolved motions seen in the
  nonthermal widths, shows the need for significant power at scales of
  10 km or less. The power, because it extends to such high wavenumbers,
  can be dissipated by viscosity and joule heating at a rate sufficient
  to maintain transition zone against its radiative losses.

---------------------------------------------------------
Title: A brief scientific history of the NRL HRTS program.
Authors: Dere, K. P.
1990ppst.conf...29D    Altcode:
  Since its first flight in 1975, the NRL High Resolution Telescope and
  Spectrograph (HRTS) has now recorded high quality ultraviolet spectra
  of the Sun on 6 rocket flights and during extended operations on the
  Space Shuttle Spacelab 2 mission in 1985.

---------------------------------------------------------
Title: The Relationship of C IV Transition Region Structures to the
    Photospheric Magnetic Field
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1990BAAS...22..744D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: High Resolution Spectrography in Ultraviolet
Authors: Schmieder, B.; Thompson, W. T.; Neupert, W. M.; Thomas,
   R. J.; Dere, K. P.
1990PDHO....7..250S    Altcode: 1990ESPM....6..250S; 1990dysu.conf..250S
  The authors point out some of the advantages of coordinated observations
  with ground-based and space instrumentation. Results obtained during
  the rocket flight of the Solar Extreme-ultraviolet Rocket Telescope
  and Spectrograph (SERTS) for a preflaring region are presented and the
  complementarity of observations is pointed out with the High Resolution
  Telescope and Spectrograph (HRTS) which permits the detection of
  dynamical structures in hot plasma surrounding cool structures such
  as prominences and sunspots seen in visible light.

---------------------------------------------------------
Title: Temperature and Center-Limb Variations of Transition Region
    Velocities
Authors: Athay, R. G.; Dere, K. P.
1989ApJ...346..514A    Altcode:
  HRTS data from the Spacelab 2 mission are used to derive the
  center-limb and temperature variations of the mean velocity and the
  velocity variance in the solar chromosphere and transition zone. The
  mean velocity is found to vary much more rapidly from center to limb
  and with temperature than does the velocity variance. Also, the mean
  velocity shows a characteristic signature at some magnetic neutral
  lines in accordance with the findings of Klimchuk (1987) from Solar
  Maximum Mission (SMM) data. The velocity variance does not show a
  characteristic signature at the neutral lines but shows an inverse
  correlation with intensity. The latter is interpreted as reduced
  velocity variance in strong field regions. The results are discussed
  in terms of downflow along lines of force in magnetic arcades.

---------------------------------------------------------
Title: Transition Zone Flows Observed in a Coronal Hole on the
    Solar Disk
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.; Recely, F.
1989ApJ...345L..95D    Altcode:
  A rocket flight of the NRL High Resolution Telescope and Spectrograph
  (HRTS) was performed to obtain ultraviolet spectra of a well-defined
  coronal hole on the solar system. Observed emission lines included
  strong transition zone lines of C IV at 1548 and 1550 A, strong
  chromospheric lines of C I near 1560 A, and chromospheric lines of Fe
  (II) at 1563 A. Continuum radiation formed in the temperature minimum
  was also recorded. The cumulative histogram of the C IV velocities in
  the coronal hole shows an average Doppler shift of 2 km/sec to the red
  (downflow) with 26 percent of the profiles having blueshifts (outflows)
  compared to 7 percent in the quiet sun. The present observations have
  the advantages of higher spatial resolution and a nearly absolute
  wavelength scale determined from narrow chromospheric lines of Si I
  with an accuracy of about 1 km/sec. The nonthermal velocities, derived
  from the C IV line widths, are only marginally larger inside the coronal
  hole than those in the quiet sun, thus indicating that the magnitude of
  small-scale motions, which may represent energy available for coronal
  heating and solar wind acceleration, is equal in the two regions.

---------------------------------------------------------
Title: Correspondence between solar fine-scale structures in the
    corona, transition region, and lower atmosphere from collaborative
    observations
Authors: Moses, J. Daniel; Cook, J. W.; Bartoe, J. -D. F.; Brueckner,
   G. E.; Dere, K. P.; Webb, D. F.; Davis, John M.; Recely, F.; Martin,
   S. F.; Zirin, H.
1989sxsr.reptR....M    Altcode:
  The Soft X-Ray Imaging Payload and the High Resolution Telescope and
  Spectrograph (HRTS) instrument were launched from White Sands on 11
  December 1987 in coordinated sounding rocket flights to investigate the
  correspondence of coronal and transition region structures, especially
  the relationship between X-ray bright points (XBPs) and transition
  region small spatial scale energetic events. The coaligned data from
  X-ray images are presented along with maps of sites of transition
  region energetic events observed in C IV (100,000 K), HRTS 1600 A
  spectroheliograms of the T<SUB>min</SUB> region and ground based
  magnetogram and He I 10830 A images.

---------------------------------------------------------
Title: Extreme ultraviolet imaging telescope on board the Solar
    Heliospheric Observatory
Authors: Delaboudiniere, Jean-Pierre; Gabriel, Alan H.; Artzner,
   Guy E.; Millier, F.; Michels, Donald J.; Dere, Kenneth P.; Howard,
   Russell A.; Kreplin, Robert W.; Catura, Richard C.; Stern, Robert A.;
   Lemen, James R.; Neupert, Werner M.; Gurman, Joseph B.; Cugnon, P.;
   Koeckelenbergh, A.; van Dessel, E. L.; Jamar, Claude A.; Maucherat,
   Andre J.; Chauvineau, Jean-Pierre; Marioge, Jean-Paul
1989SPIE.1160..518D    Altcode: 1989xeoa.conf..518D
  The design of the multibandpass Extreme-Ultraviolet Imaging Telescope
  designed for 1996 launch on board the Solar Heliospheric Observatory
  is described. The telescope will observe simultaneously distinct
  temperature ranges in the solar corona, defined by well chosen emission
  lines. Images in four narrow bandpasses at wavelengths ranging from 17
  to 31 nm will be obtained using normal-incidence multilayered optics
  deposited on quadrants of a Ritchey-Chretien telescope. Results are
  presented on the performances measured on a 2/3 scale mock-up. The
  bandpasses could be adjusted to better than 1 percent in wavelength.

---------------------------------------------------------
Title: Turbulent Power and Dissipation in the Solar Transition Zone
Authors: Dere, Kenneth P.
1989ApJ...340..599D    Altcode:
  The power spectrum of the spatial velocity fluctuations of the solar
  transition zone are determined from high-resolution telescope and
  spectrograph solar spectra of C IV. It is found that virtually all of
  the power resides at higher wavenumbers and that the spectrum is flatter
  than predicted for the inertial range of a turbulent fluid. The results
  suggest that the small-scale fluctuations are maintained by a driving
  mechanism such as magnetic reconnection or wave motions produced in
  the photosphere.

---------------------------------------------------------
Title: Dynamics of a filament at the boundary of a SPOT region with
    magnetic shear
Authors: Schmiedler, B.; Demoulin, P.; Raadu, M. A.; Dere, K. P.
1989A&A...213..402S    Altcode:
  H-alpha (MSDP), magnetograph (Meudon), and C IV (HRTS) observations are
  used to investigate the relationship between the dynamics of a solar
  filament and a spot region with vortex structure. Comparisons are made
  between the structures in H-alpha and C IV intensity and Doppler-shift
  images. These show filament shearing and a good correlation between
  H-alpha and C IV upflow, the C IV filament being very dynamic (+ or -
  50 km/s). Magnetograph data for the whole region including the sunspot
  are used to calculate linear force-free fields. The magnetic structure
  at the filament is found to be favorable for support.

---------------------------------------------------------
Title: The HRTS Guest Investigator Program
Authors: Lund, P.; Ewing, J.; Cook, J.; Dere, K.; Brueckner, G.
1989BAAS...21..841L    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Comparison of HRTS Sounding Rocket Observations at 1600 Å
    and Hα with Groundbased Magnetograms and He I 10830 Å Images
Authors: Cook, J. W.; Bartoe, J. -D. F.; Brueckner, G. E.; Dere, K. P.
1989BAAS...21..840C    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Ultraviolet Observations of Macrospicules at the Solar Limb
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.; Cook,
   J. W.; Socker, D. G.; Ewing, J. W.
1989SoPh..119...55D    Altcode:
  During the Spacelab 2 mission, the NRL High Resolution Telescope and
  Spectrograph (HRTS) obtained a time-series of broad-band ultraviolet
  images of macrospicules at the solar limb inside a polar coronal
  hole with a temporal resolution of 20 and 60 s. The properties of the
  macrospicules observed in the Spacelab data are measured and compared
  with the properties reported for EUV macrospicules observed during
  Skylab (Bohlin et al., 1975; Withbroe et al., 1976). There is a general
  agreement between the data sets but several differences. Because of
  the higher temporal resolution of the Spacelab data, it is possible
  to see macrospicules with shorter lifetimes than seen during Skylab,
  as well as variations on faster timescales. The largest (30-60') and
  fastest (150 km s <SUP>-1</SUP>) macrospicules seen during Skylab were
  not found in the Spacelab observations. The Spacelab data support the
  conclusion that many macrospicules decay by simply fading away.

---------------------------------------------------------
Title: Explosive Events in the Solar Transition Zone
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1989SoPh..123...41D    Altcode:
  The properties of explosive events in the solar transition zone are
  presented by means of detailed examples and statistical analyses. These
  events are observed as regions of exceptionally high velocity (∼
  100 km s<SUP>−1</SUP>) in profiles of CIV, formed at 10<SUP>5</SUP>
  K, observed with the High Resolution Telescope and Spectrograph
  (HRTS). The following average properties have been determined from
  observations obtained during the third rocket flight of the HRTS: full
  width at half maximum extent along the slit - 1.6 × 10<SUP>3</SUP> km;
  maximum velocity - 110 km s<SUP>−1</SUP>; peak emission measure -
  4 × 10<SUP>41</SUP> cm<SUP>−3</SUP>; lifetime - 60 s; birthrate -
  4 × 10<SUP>−21</SUP> cm<SUP>−2</SUP> s<SUP>−1</SUP> in a coronal
  hole and 1 × 10<SUP>−20</SUP> cm<SUP>−2</SUP> s<SUP>−1</SUP>
  in the quiet Sun; mass - 6 × 10<SUP>8</SUP> g; and, kinetic energy - 6
  × 10<SUP>22</SUP> erg. The 6 examples show that there are considerable
  variations from these average parameters in individual events. Although
  small, the events show considerable spatial structure and are not
  point-like objects. A spatial separation is often detected between the
  positions of the red and blue shifted components and consequently the
  profile cannot be explained by turbulence alone. Mass motions in the
  events appear to be isotropic because the maximum observed velocity
  does not show any correlation with heliographic latitude. Apparent
  motions of the 100 km s<SUP>−1</SUP> plasmas during their 60 s
  lifetime should be detected but none are seen. The spatial frequency
  of occurrence shows a maximum near latitudes of 40-50°, but otherwise
  their sites seem to be randomly distributed. There is enough mass in
  the explosive events that they could make a substantial contribution
  to the solar wind. It is hard to explain the heating of typical quiet
  structures by the release of energy in explosive events.

---------------------------------------------------------
Title: HRTS Transition Region Observations of a Coronal Hole on the
    Solar Disk
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1989BAAS...21..841D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: A Model for the Heating of the Transition Region
Authors: Antiochos, S. K.; Dere, K. P.
1989BAAS...21..841A    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Magnetic Associations of Explosive Events
Authors: Porter, J. G.; Dere, K. P.
1989BAAS...21..852P    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Plasma Motions in an Emerging Flux Region
Authors: Brueckner, G. E.; Bartoe, J. -D. F.; Cook, J. W.; Dere,
   K. P.; Socker, D.; Kurokawa, H.; McCabe, M.
1988ApJ...335..986B    Altcode:
  Ultraviolet spectra of C IV show large nonthermal broadening in an
  area of emerging flux. These nonthermal motions are observed at a very
  early stage of reconnecting field lines. The spectra can be traced
  to small, rapidly changing surge or filament-like features which
  are seen in the center, blue, and red wing of H-alpha. They seem to
  have the characteristics of macrospicules or explosive events. They
  are precursors of the reconnection process. Plasma turbulence and/or
  plasma waves in the reconnecting plasma may cause the broad C IV line
  profiles. The activity in the transition zone precedes the formation
  of a bright chromospheric loop system.

---------------------------------------------------------
Title: LASCO: A wide-field white light and spectrometric coronagraph
    for SOHO
Authors: Michels, D. J.; Schwenn, R.; Howard, R. A.; Bartoe, J. -D. F.;
   Antiochos, S. K.; Brueckner, G. E.; Cheng, C. -C.; Dere, K. P.;
   Doschek, G. A.; Mariska, J. T.
1988sohi.rept...55M    Altcode:
  The scientific objectives of the LASCO (light and spectrometric
  coronagraph) project in the SOHO (solar and heliospheric observatory)
  mission are described. These include investigation of mechanisms
  for heating of the corona and acceleration of the solar wind, causes
  of coronal transients, and their role in development of large scale
  coronal patterns and interplanetary disturbances. The distribution
  and properties of dust particles, including those released from
  sun-grazing comets are investigated. Interactions of coronal plasma
  with the dust are studied. The corona is analyzed spectroscopically
  by a high-resolution scanning, imaging interferometer. The spectral
  profiles of three emission lines and one Fraunhofer line are measured
  for each picture point, giving temperatures, velocities, turbulent
  motions and volume densities. Polarization analysis yields the direction
  of coronal magnetic fields.

---------------------------------------------------------
Title: Gas Flows in the Transition Region above Sunspots
Authors: Kjeldseth-Moe, O.; Brynildsen, N.; Brekke, P.; Engvold, O.;
   Maltby, P.; Bartoe, J. -D. F.; Brueckner, G. E.; Cook, J. W.; Dere,
   K. P.; Socker, D. G.
1988ApJ...334.1066K    Altcode:
  Strong downflows and moderate upflows in the transition region over
  a sunspot have been observed with the HRTS on Spacelab 2 in 1985. The
  flows are persistent in the sense that they are seen in the same spot
  for 5 days. The downflows are prominent in regions of limited extent
  (4arcsec - 6arcsec), and flow velocities are in the range 40 - 80 km
  s<SUP>-1</SUP> and are thus supersonic. Upward flows have smaller
  velocities, 5 - 20 km s<SUP>-1</SUP>, but may extend over a larger
  area. In the downflowing regions there is always an appreciable amount
  of gas at rest in the line of sight. Flow speeds derived from the
  profiles of different lines formed in the transition region between
  30,000 and 230,000K are very similar implying constant downflow in
  this temperature range.

---------------------------------------------------------
Title: EIT: Solar corona synoptic observations from SOHO with an
    Extreme-ultraviolet Imaging Telescope
Authors: Delaboudiniere, J. P.; Gabriel, A. H.; Artzner, G. E.;
   Michels, D. J.; Dere, K. P.; Howard, R. A.; Catura, R.; Stern, R.;
   Lemen, J.; Neupert, W.
1988sohi.rept...43D    Altcode:
  The Extreme-ultraviolet Imaging Telescope (EIT) of SOHO (solar and
  heliospheric observatory) will provide full disk images in emission
  lines formed at temperatures that map solar structures ranging from
  the chromospheric network to the hot magnetically confined plasma in
  the corona. Images in four narrow bandpasses will be obtained using
  normal incidence multilayered optics deposited on quadrants of a
  Ritchey-Chretien telescope. The EIT is capable of providing a uniform
  one arc second resolution over its entire 50 by 50 arc min field of
  view. Data from the EIT will be extremely valuable for identifying
  and interpreting the spatial and temperature fine structures of the
  solar atmosphere. Temporal analysis will provide information on the
  stability of these structures and identify dynamical processes. EIT
  images, issued daily, will provide the global corona context for aid
  in unifying the investigations and in forming the observing plans for
  SOHO coronal instruments.

---------------------------------------------------------
Title: The Correspondence Between Fine-Scale Structures in the Solar
    Corona and Transition Region
Authors: Moses, J. D.; Bartoe, J. -D. F.; Brueckner, G. E.; Cook,
   J. W.; Dere, K. P.; Davis, J. M.; Webb, D.
1988BAAS...20..722M    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Correlation of Transition Region C IV High-Velocity Events
    With Magnetogram and He I 10830 Å Data
Authors: Cook, J. W.; Bartoe, J. -D. F.; Brueckner, G. E.; Dere,
   K. P.; Recely, F.; Martin, S.; Zirin, H.
1988BAAS...20..722C    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The Power Spectrum of Velocities in the Solar Transition Zone
Authors: Dere, K. P.
1988BAAS...20..722D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Solar physics from Spacelab 2.
Authors: Dere, K. P.
1988JPhys..49....3D    Altcode: 1988IAUCo.102....3D
  Four instruments were flown aboard the Spacelab 2 shuttle mission
  to perform systematic observations of the solar atmosphere at high
  resolution and to measure specific global properties of the sun. The
  Solar Optical Universal Polarimeter recorded series of white light
  images with which the evolution of the granulation and sunspot
  phenomena have been studied. The Coronal Helium Abundace Shuttle
  Experiment provided measurements of a number of EUV coronal lines, and,
  in particular, the intensities of He II λ304 and H I λ1216 from which
  the coronal helium abundance can be determined. The High Resolution
  Telescope and Spectrograph obtained stigmatic spectra in the 1200 -
  1700 Å wavelength range, as well as broad band UV spectroheliograms, to
  provide diagnostic information on the solar chromosphere and transition
  zone. The Solar Ultraviolet Spectral Irradiance Monitor measured the
  total solar irradiance at a resolution of 1.5 and 50 Å in the 1200
  to 4000 Å wavelength range to an accuracy of 3%.

---------------------------------------------------------
Title: Results from the High Resolution Telescope and Spectrograph
    (HRTS) Experiment on Board Spacelab 2
Authors: Brueckner, G. E.; Bartoe, J. -D. F.; Cook, J. W.; Dere,
   K. P.; Socker, D. G.
1988ApL&C..27..151B    Altcode:
  Several papers including reviews have been published during different
  stages of the data analysis after the SL-2 flight. In order to avoid
  repetition, this article lists all publications and briefly mentions
  some of the highlights.

---------------------------------------------------------
Title: Ultraviolet Observations of Solar Fine Structure
Authors: Dere, Kenneth P.; Bartoe, John-David F.; Brueckner, Guenter
   E.; Cook, John W.; Socker, Dennis G.
1987Sci...238.1267D    Altcode:
  The High Resolution Telescope and Spectrograph was flown on the
  Spacelab-2 shuttle mission to perform extended observations of the
  solar chromosphere and transition zone at high spatial and temporal
  resolution. Ultraviolet spectroheliograms show the temporal development
  of macrospicules at the solar limb. The C IV transition zone emission
  is produced in discrete emission elements that must be composed of
  exceedingly fine (less than 70 kilometers) subresolution structures.

---------------------------------------------------------
Title: Chromospheric and Transition Zone Flows in a Solar Active
    Region
Authors: Dere, K. P.; Schmieder, B.
1987BAAS...19.1118D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Discrete Subresolution Structures in the Solar Transition Zone
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.; Cook,
   J. W.; Socker, D. G.
1987SoPh..114..223D    Altcode:
  During operations on the Spacelab-2 Shuttle mission, the NRL High
  Resolution Telescope and Spectrograph (HRTS) recorded spectra of a
  variety of solar features in the 1200-1700 Å wavelength region which
  contains spectral lines and continua well suited for investigating
  the temperature minimum, the chromosphere and transition zone. These
  data show that, at the highest spatial resolution, the transition zone
  spectra are broken up from a continuous intensity distribution along
  the slit into discrete emission elements. The average dimensions
  of these discrete transition zone structures is 2400 km along the
  slit, but an analysis of their emission measures and densities shows
  that the dimensions of the actual emitting volume is conciderably
  less. If these structures are modelled as an ensemble of subresolution
  filaments, we find that these filaments have typical radii of from
  3 to 30 km and that the cross-sectional fill factor is in the range
  from 10<SUP>−5</SUP> to 10<SUP>−2</SUP>. The transport of mass
  and energy through these transition zone structures is reduced by
  this same factor of 10<SUP>−5</SUP> to 10<SUP>−2</SUP> which has
  significant consequences for our understanding of the dynamics of the
  solar atmosphere. Because the HRTS transition zone line profiles are
  not broadened by resolved large-spatial-scale solar velocity fields,
  the line widths of the CIV lines have been analyzed. The average line
  width is 0.195 Å (FWHM) and requires an average nonthermal velocity
  of 16 km s<SUP>−1</SUP> (most-probable) or 19 km s<SUP>−1</SUP>
  (root-mean-square) which is lower than previously observed values.

---------------------------------------------------------
Title: Transition Zone Flow Patterns in Sunspots
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.; Cook,
   J. W.; Socker, D. G.
1987BAAS...19..639D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Statistical Properties of Small High-Velocity Events in the
    Solar Transition Region
Authors: Cook, J. W.; Lund, P. A.; Bartoe, J. -D. F.; Brueckner,
   G. E.; Dere, K. P.; Socker, D. G.
1987LNP...291..150C    Altcode: 1987csss....5..150C
  We discuss the energy contribution of small high-velocity events
  observed in the solar transition region to atmospheric heating. These
  events do not directly provide enough energy to heat the atmosphere,
  but are instead after-products of turbulent energy dissipation at the
  sites of the actual primary nonthermal heating process.

---------------------------------------------------------
Title: Identification of [Fe III] in the solar ultraviolet spectrum
Authors: Jordan, C.; Bartoe, J. -D. F.; Brueckner, G. E.; Dere, K. P.
1986Natur.324..444J    Altcode:
  Solar ultraviolet spectra have been obtained with high spectral and
  spatial resolution using the Naval Research Laboratory's high-resolution
  telescope and spectrograph<SUP>1</SUP> (HRTS) flown on rockets since
  1975 and most recently on the Spacelab 2 Shuttle flight. Because the
  solar spectrum between ~1,170 and 1,719 Å has been well observed for
  some years, few lines of substantial intensity remain unidentified. (See
  for example the recent compilation by Sandlin et al.<SUP>2</SUP>). The
  longest exposures during the first rocket flight of the HRTS, which
  obtained spectra with a spatial resolution of ~ 1 arc s along the slit,
  of length ~ 1 solar radius, and a spectral resolution of ~0.05 Å,
  showed a number of weak emission lines at the solar limb, in particular
  between 1,570 and 1,600 Å (see Plates 16 and 17 in ref. 3), that could
  not readily be identified. Improved observations of these lines were
  obtained during the flight of HRTS on the Spacelab 2 Shuttle flight in
  July-August 1985, by making longer exposures (60,100 and 250 s). The
  scope of the data obtained has been described<SUP>4</SUP>. We have
  now identified the emission lines concerned as forbidden (electric
  quadrupole and magnetic dipole) transitions in Fe III, the first
  detection of these particular transitions in any source. They must now
  be considered potential candidates for previously unidentified lines in
  other low-density (N<SUB>e</SUB> &lt;~ 10<SUP>10</SUP> cm<SUP>-3</SUP>)
  astrophysical sources.

---------------------------------------------------------
Title: Outflows and Ejections in the Solar Transition Zone
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1986ApJ...310..456D    Altcode:
  Time series images of C IV transition zone intensities and velocities
  are analyzed to study the uncommon patterns of blueshifted emission. The
  images are constructed from stigmatic spectra obtained during the third
  flight of the NRL High Resolution Telescope and Spectrograph. A sample
  of 11 blueshifted events with near-Gaussian profiles are analyzed. Of
  these 11 cases, three are expulsions of material from the network, two
  are spicular flows, one is a simple jet, another is associated with
  a filament, and four are unexplained. It is not possible to identify
  a simple mechanism whereby upflows return to form the predominant
  downflows observed in the transition zone, and the upward mass flux
  is three orders of magnitude lower than the downward mass flux.

---------------------------------------------------------
Title: Observation of the Density Sensitive Line Mg V 1324 Å in a
    Solar Sunspot
Authors: Cook, J. W.; Socker, D. G.; Bartoe, J. -D. F.; Brueckner,
   G. E.; Dere, K. P.
1986BAAS...18R.991C    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Culgoora Radio and SKYLAB Extreme Ultraviolet Observations
    of Emerging Magnetic Flux in the Lower Corona
Authors: Stewart, R. T.; Brueckner, G. E.; Dere, K. P.
1986SoPh..106..107S    Altcode:
  Detailed comparisons of Culgoora 160 MHz radioheliograms of solar noise
  storms and Skylab EUV spectroheliograms of coronal loop structures
  are presented. It is concluded that: (1) there is a close association
  between changes in large-scale magnetic fields in the corona and
  the onset or cessation of noise storms; (2) these coronal changes
  result from the emergence of new magnetic flux at the photospheric
  level; (3) although new magnetic flux at the photospheric level is
  often accompanied by an increase in flare activity the latter is
  not directly responsible for noise storm activity; rather the new
  magnetic flux diffuses slowly outwards through the corona at rates
  ∼1-2 km s<SUP>−1</SUP> and produces noise storms at 160 MHz 1-2
  days later; (4) the coronal density above or in large-scale EUV loop
  systems is sufficiently dense to account for noise storm emission
  at the fundamental plasma frequency; (5) the scatter in noise storm
  positions can be accounted for by the appearance and disappearance of
  individual loops in a system.

---------------------------------------------------------
Title: High-Resolution Telescope and Spectrograph Images of the
    Solar Chromosphere and Transition Zone
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1986ApJ...305..947D    Altcode:
  Observations of a 10-arcsec-wide 800-arcsec-long region of the
  southern solar hemisphere, obtained at 150-160 nm by the rocket-borne
  High-Resolution Telescope and Spectrograph on March 1, 1979, are
  reported and analyzed. Rastered stigmatic spectra are reduced to create
  color images of intensity, Doppler shift, and line width providing
  information on the UV structure of the solar atmosphere. Characteristics
  discussed include temperature stratification in quiet-sun network
  elements; chromospheric jets appearing at supergranular cell centers;
  general redshift of 5 km/s in quiet-sun C IV; downflow patterns in C
  IV, Fe II, and C I; plage structures with temperature stratification
  and 6-km/s C IV downflow; and faint filament emission with blueshifts
  near the top and redshifts at the sides in the C IV images.

---------------------------------------------------------
Title: Discrete Components of Solar Transition Zone Emission
Authors: Dere, K. P.; Brueckner, G. E.; Bartoe, J. -D. F.; Cook,
   J. W.; Socker, D. G.
1986BAAS...18Q.662D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Statistical Properties of Small High-Velocity Transition
    Region Events on the Sun Observed by HRTS on Spacelab 2
Authors: Cook, J. W.; Lund, P. A.; Brueckner, G. E.; Bartoe, J. -D. F.;
   Dere, K. P.; Socker, D. G.
1986BAAS...18..662C    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Results from the High Resolution Telescope and Spectrograph
    (HRTS) Experiment
Authors: Brueckner, G. E.; Cook, J. W.; Dere, K. P.
1986BAAS...18..675B    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: HRTS Spacelab 2 Observations of the Temporal Development of
    the C IV Transition Zone
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.; Cook,
   J. W.; Lund, P.; Socker, D. G.
1986BAAS...18..633D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: HRTS results from spacelab 2
Authors: Brueckner, G. E.; Bartoe, J. -D. F.; Cook, J. W.; Dere,
   K. P.; Socker, D. G.
1986AdSpR...6h.263B    Altcode: 1986AdSpR...6..263B
  The HRTS instrument flew on the Spacelab 2 mission from 29 July -
  6 August 1985. HRTS consisted of a 30 cm Gregorian telescope, a slit
  spectrograph covering the 1190-1680 Å region with 0.05 Å spectral
  resolution, a broadband (90 Å FWHM) spectroheliograph tuned to 1550
  Å, and an H-alpha filter system. The spectrograph slit was 920 arc
  sec, approximately 1 R<SUB>0</SUB>, in length. Sub arc second spatial
  resolution along the slit is possible, but because of jitter in the
  Spacelab Instrument Pointing System (IPS) good exposures actually
  achieved 1-2 arc sec resolution. We describe the scientific results
  from HRTS.

---------------------------------------------------------
Title: Results from the NRL instruments on Spacelab 2
Authors: Bartoe, J. -D. F.; Brueckner, G. E.; Cook, J. W.; Dere,
   K. P.; Morrison, M. D.
1986aiaa.meetZ....B    Altcode:
  The instrumental features of the high resolution Telescope and
  spectrograph (HRTS) and the solar UV spectral irradiance monitor
  (SUSIM) used for solar observations on the Spacelab 1 mission are
  described. The HRTS has three focal plane instruments receiving light
  from a 30 cm aperture furnishing at 15 X 15 arcmin FOV which can
  be modified for slit photography and raster scans. The focal plane
  instruments are a spectrograph, spectroheliograph and a television
  camera and photographic film fronted by a mica Fabry-Perot filter. About
  13 hr of solar observations were made with the HRTS during the 8
  day mission. Sample spectral and photographic data are provided and
  discussed. SUSIM is an UV spectrometer with redundant optical paths for
  in-flight calibration with a D2 lamp. It is sensitive in the 1200-4000
  A range. Several wavelength ranges are evaluated. Particular attention
  is given to multitemporal Ly-alpha recordings.

---------------------------------------------------------
Title: HRTS Spacelab 2 Observations of Spicular Emission at the
    Solar Limb
Authors: Cook, J. W.; Bartoe, J. -D. F.; Brueckner, G. E.; Dere,
   K. P.; Socker, D. G.
1985BAAS...17..834C    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Ultraviolet Observations of Fine Structure in the Solar
    Chromosphere and Transition Zone
Authors: Dere, K.
1985tphr.conf..233D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Time Series Images of the UV Chromosphere and Transition Zone
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1985BAAS...17..630D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Report of the working group on future observations of the sun.
Authors: Dere, K.; Kneer, F.; Landman, D.
1985cdm..proc...14D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: HRTS observations of the solar chromosphere and transition
    zone.
Authors: Dere, K. P.
1985cdm..proc...50D    Altcode:
  The NRL High Resolution Telescope and Spectrograph (HRTS) consists
  of a 30 cm Cassegrain telescope which focuses an image of the sun
  with 1 arcsec resolution, a stigmatic tandem-Wadsworth mount UV
  spectrograph, a UV broadband spectroheliograph and H-alpha film
  and video cameras. Images of the UV line and continuum intensities
  show that they are all strongly associated with the chromospheric
  network, with an almost one-to-one correspondence found between Fe II
  intensity images and H-alpha -0.6 A spectroheliograms. The region of
  C IV emission occurs above the chromospheric mottles at a height of
  3900 km when the continuum height is placed at 500 km; significant C
  IV transition-zone emission was also found at the base of the network
  elements. C IV profiles are generally near Gaussian, with dimensions on
  the order of 200 km. Time series and velocity field data are provided,
  and it is concluded that a steady state heating mechanism is present
  in the chromosphere.

---------------------------------------------------------
Title: UV observations of fine structure in the solar chromosphere
    and transition zone.
Authors: Dere, K. P.
1985MPARp.212..233D    Altcode:
  The capabilities of the NRL High Resolution Telescope and Spectrograph
  (HRTS) made it possible to obtain UV spectra at a spatial resolution
  sufficient to resolve fine structures in the solar chromosphere and
  transition zone. To date, it has made observations during 4 rocket
  flights and recently obtained highly successful longer term observations
  during the Spacelab-2 mission. Obviously, only the rocket spectra
  have been analyzed in any detail. The author addresses three areas
  where the understanding of the solar chromosphere and transition zone,
  based on these HRTS observations, may need reassessment.

---------------------------------------------------------
Title: High-resolution telescope and spectrograph observations of
    the quiet solar chromosphere and transition zone
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1984ApJ...281..870D    Altcode:
  A systematic program to observe the two-dimensional structure of the
  solar atmosphere and its temporal variation was conducted in connection
  with the third rocket flight of the High Resolution Telescope and
  Spectrograph (HRTS). A description is presented of the manner in which
  line intensities, Doppler shifts (velocities), and line widths are
  obtained from HRTS spectra. These quantities are derived for a single
  stigmatic slit spectra of the quiet sun. It is pointed out that an
  accurate wavelength scale can be derived from narrow Si I lines in
  the spectra. The intensity of chromospheric lines such as C I lambda
  1560 is found to be largely the result of the structures forming the
  chromospheric network. A number of conclusions are drawn about quiet
  transition zone Doppler shifts (flows).

---------------------------------------------------------
Title: Ultraviolet spectroscopy of the chromosphere and transition
    zone at high spatial and temporal resolution
Authors: Dere, K. P.
1984AdSpR...4h..55D    Altcode: 1984AdSpR...4...55D
  The third rocket flight of the NRL High Resolution Telescope and
  Spectrograph (HRTS) recorded UV spectra of the quiet Sun in a 10”
  × 800” region. By rastering the slit in 2” increments, a time
  series with 20s resolution of two-dimensional spectra with 1” spatial
  resolution was obtained. The spectrum includes strong chromospheric
  diagnostic lines of C I, Si I, and Fe II, transition zone lines of C IV
  and the continuum which is produced in the temperature minimum. Images
  of the network show that Fe II emission is well-correlated with
  dark Hα mottles, that the transition zone is produced in extended
  structures which are apparently continuations of the mottles, and
  that the strongest continuum emission is from near the base of the
  mottles. Time series of C I profiles show little variation in most
  features aside from the chromospheric jets which develop rapidly over
  timescales of 30s. The C IV profiles also show only gradual variations
  over most of the slit except for the numerous small explosive events.

---------------------------------------------------------
Title: HRTS Ultraviolet Images of the Solar Chromosphere and
    Transition Zone
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1984LNP...193..180D    Altcode: 1984csss....3..180D
  No abstract at ADS

---------------------------------------------------------
Title: HRTS Ultraviolet Solar Spectroscopy (invited Paper)
Authors: Dere, K. P.
1984uxsa.coll...22D    Altcode: 1984IAUCo..86...22D; 1984uxsa.conf...22D
  No abstract at ADS

---------------------------------------------------------
Title: HRTS observations of the fine structure and dynamics of the
    solar chromosphere and transition zone.
Authors: Dere, K. P.
1983NASCP.2280..33D    Altcode: 1983sowi.conf...33D
  Arc-second UV observations of the Sun by the NRL High Resolution
  Telescope and Spectrograph (HRTS) have led to the discovery of
  dynamic fine structures such as 400 km s<SUP>-1</SUP> coronal jets and
  chromospheric jets (spicules) and have provided new information about
  the structure and dynamics of the transition zone. These observations
  are reviewed and their relevance to the origin of the solar wind
  is discussed.

---------------------------------------------------------
Title: Mass and energy balance in the 1973 August 9 flare
Authors: Dere, K. P.; Cook, J. W.
1983A&A...124..181D    Altcode:
  The mass and energy balance of the thermal plasma during the decay
  phase of the solar flare of August 9, 1973, are studied. The analysis
  is based on observationally determined values for the differential
  emission measure, density, turbulent and bulk velocities, and
  physical dimensions. The total particle content and total thermal
  energy content of the flare plasmas with temperatures above 100,000 K
  and their variation with time are calculated. The particle loss and
  the energy losses through radiation, conduction, and convection are
  evaluated. The decrease in total particle content can be accounted
  for by the convective losses through the loop footprints at 100,000
  K. Radiation is the dominant energy loss mechanism although convective
  losses at 100,000 K can be important. Conductive losses at 100,000
  K into cooler chromospheric material appear to be negligible. The
  decrease in the total energy content during the decay phase is equal
  to the sum of the energy losses over the period of observation. No
  requirement is found for continued heating during the decay phase.

---------------------------------------------------------
Title: Chromospheric jets - Possible extreme-ultraviolet observations
    of spicules
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1983ApJ...267L..65D    Altcode:
  Stigmatic EUV spectra of chromospheric lines obtained by the Naval
  Research Laboratory High Resolution Telescope and Spectrograph (HRTS)
  show small arc second regions with strong (10-20 km/s) Doppler shifts
  which are called 'chromospheric jets'. Because of the strong resemblance
  of their physical and statistical properties, such as temperature,
  density, velocity, size, and birthrate, to those of visible light
  spicules, it is highly likely that they are different manifestations
  of the same phenomena, although a one-to-one identification has not yet
  been made. The main difference is the 40 s lifetime of the chromospheric
  jets which is shorter than the 5 minute lifetime of visible light
  spicules. The chromospheric jets are found in the supergranular cell
  interiors where chromospheric and transition zone line intensities
  are weak. Dark H-alpha mottles found in the cell boundaries are well
  correlated with intense, symmetric chromospheric EUV line profiles
  and are only weakly related to the chromospheric jets.

---------------------------------------------------------
Title: HRTS Images of the Quiet Solar Chromosphere and Transition Zone
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1983BAAS...15..702D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The NRL SOLRAD 11 Satellites (1976-023C, 1976-023D) description
    of experiments
Authors: Horan, D. M.; Kreplin, R. W.; Dere, K. P.
1982nrl..reptY....H    Altcode:
  The Naval Research Laboratory's SOLRAD 11 satellites were successfully
  launched on 15 March 1976. The two satellites each carried an identical
  complement of 25 experiments to measure solar electromagnetic and
  charged particle emissions, Earth auroral and stellar X-ray emission,
  terrestrial and interplanetary extreme ultraviolet emission, X-ray and
  charged particle emission from the anti-solar direction, and gamma
  ray bursts. This report provides general descriptive information on
  the satellites and their sensors.

---------------------------------------------------------
Title: Observations of Extreme Ultraviolet Spicules
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1982BAAS...14..939D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Solar transition zone pressures from EUV observations of O
    IV and N IV
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1982ApJ...259..366D    Altcode:
  NRL High Resolution Telescope and Spectrograph observations of the O
  IV and N IV EUV lines emitted from the Sun are examined. The instrument
  provides stigmatic spectra with a spatial resolution of 1 arcsec and a
  spectral resolution of 0.05 A in the range 1170-1710 A. Intensity ratios
  of the intersystem lines of O IV near 1400 A are used as the primary
  diagnostic to measure electron pressures in a sunspot and plage. These
  ratios are strongly sensitive to electron pressure but are insensitive
  to the temperature structure of the emitting plasma. Average electron
  pressures of 9 x 10 to the 15th per cu cm K (1.2 dyn/sq cm) in a plage,
  4 x 10 to the 15th per cu cm K (0.6 dyn/sq cm) in a sunspot and 2.2 x 10
  to the 15th per cu cm K (0.3 dyn/sq cm) in high speed sunspot downflows
  are found. The ratio of I(Nv) + I(C IV) to I(N IV 1486A) is shown to
  be relatively insensitive to temperature and gives pressures consistent
  with those obtained from the O IV ratio. It is demonstrated that ratios
  of allowed lines such as C IV and Si IV to the O IV intersystem lines
  are temperature sensitive and hence are unreliable pressure diagnostics.

---------------------------------------------------------
Title: Extreme Ultraviolet Spectra of Solar Active Regions and
    Their Analysis
Authors: Dere, K. P.
1982SoPh...77...77D    Altcode:
  Extreme ultraviolet spectra of several active regions are presented
  and analyzed. Spectral intensities of 3 active regions observed with
  the NRL Skylab XUV spectroheliograph (170-630 Å) are derived. From
  this data density sensitive line ratios of Mg VIII, Si X, S XII,
  Fe IX, Fe X, Fe XI, Fe XII, Fe XIII, Fe XIV, and Fe XV are examined
  and typically yield, to within a factor of 2, electron pressures
  of 1 dyne cm<SUP>−2</SUP> (n<SUB>e</SUB>T = 6 × 10<SUP>15</SUP>
  cm<SUP>−3</SUP> K). The differential emission measure of the brightest
  35″ × 35″ portion of an active region is obtained between 1.4
  × 10<SUP>4</SUP> K and 5 × 10<SUP>6</SUP> K from HCO OSO-VI XUV
  (280-1370 Å) spectra published by Dupree et al. (1973). Stigmatic EUV
  spectra (1170-1710 Å) obtained by the NRL High Resolution Telescope
  and Spectrograph (HRTS) are also presented. Doppler velocities as a
  function of position along the slit are derived in an active region
  plage and sunspot. The velocities are based on an absolute wavelength
  scale derived from neutral chromospheric lines and are accurate to ±2
  km s<SUP>−1</SUP>. Downflows at 10<SUP>5</SUP> K are found throughout
  the plage with typical velocities of 10 km s<SUP>−1</SUP>. In
  the sunspot, downflows are typically 5 to 20 km s<SUP>−1</SUP>
  over the umbra and zero over the penumbra. In addition localized 90
  and 150 km s<SUP>−1</SUP> downflows are found in the umbra in the
  same 1″ × 1″ resolution elements which contain the lower velocity
  downflows. Spectral intensities and velocities in a typical plage 1″
  resolution element are derived. The velocities are greatest (∼ 10 km
  s<SUP>−1</SUP>) at 10<SUP>5</SUP> K with lower velocities at higher
  and lower temperatures. The differential emission measure between 1.3
  × 10<SUP>4</SUP> K and 2 × 10<SUP>6</SUP> K is derived and is found to
  be comparable to that derived from the OSO-VI data. An electron pressure
  of 1.4 dynes cm<SUP>−2</SUP> (n<SUB>e</SUB>T = 1.0 × 10<SUP>16</SUP>
  cm<SUP>−3</SUP> K) is determined from pressure sensitive line ratios
  of Si III, O IV, and N IV. From the data presented it is shown that
  convection plays a major role in determining the structure and dynamics
  of the active region transition zone and corona.

---------------------------------------------------------
Title: The XUV structure of solar active regions
Authors: Dere, K. P.
1982SoPh...75..189D    Altcode:
  XUV spectroheliograms of 2 active regions are studied. The images are
  due to lines emitted at temperatures between 8 x 10<SUP>4</SUP> K and
  2 x 10<SUP>6</SUP> K and thus are indicative of transition region and
  coronal structures. The hot coronal lines are formed solely in loop
  structures which connect regions of opposite photospheric magnetic
  polarity but are not observed over sunspots. Transition region lines are
  emitted in plages overlying regions of intense photospheric magnetic
  field and in loops or loop-segments connecting such regions. The
  hot coronal loops are supported hydrostatically while only some of
  the transition zone loops are. The coronal and transition zone loops
  are distinctly separated and are not coaxial. A comparison of direct
  measurements of electron densities using density sensitive line ratios
  with indirect measurements using emission measures and path lengths
  shows the existence of fine structures of less than a second of arc
  in transition region loops. From a similar analysis, hot coronal loops
  do not have any fine structure below about 2 seconds of arc.

---------------------------------------------------------
Title: Transient plasmas in the solar transition zone
Authors: Dere, K. P.; Bartoe, J. -D.; Brueckner, G. E.; Vanhoosier,
   M. E.; Dykton, M. D.
1981ApJ...249..333D    Altcode:
  Observations of C IV emission from the transition zone of the quiet
  sun have been obtained with high spatial (1 arcsec), spectral (0.1
  A), and temporal (20 s) resolution by a high resolution telescope
  and spectrograph. Over spatial scales of several arc seconds, the C
  IV profile often exhibits dramatic changes in either the red or blue
  wing or in the overall profile at the 20 s temporal resolution of the
  observations. It is suggested that some of the rapidly varying emission
  may be produced by radiatively cooling plasmas that result from the
  thermal instability of coronal plasma. It is shown that such plasmas,
  which are in transient ionization, can emit 35 s pulses of C IV emission
  for reasonable pressure values. It is also shown that, because of the
  limited ability of coronal plasma to maintain ionization equilibrium,
  the criteria for the thermal radiative instability must be evaluated
  in a manner different from the standard treatment in the case of rapid
  perturbations or growth times. From a consideration of length scales
  it is determined that these instabilities are most likely to occur in
  the upper transition zone.

---------------------------------------------------------
Title: HRTS Observations of the Solar Chromosphere and Transition Zone
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1981BAAS...13..845D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Extreme Ultraviolet Emission of O IV and N IV from the Sun
Authors: Dere, K. P.; Bartoe, J. -D. F.; Brueckner, G. E.
1981BAAS...13R.542D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Mass and Energy Balance in the 1973 August 9 Flare
Authors: Cook, J. W.; Dere, K. P.
1981BAAS...13..554C    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Spectroscopic diagnostics of the active region: transition
    zone and corona.
Authors: Dere, K. P.; Mason, H. E.
1981sars.work..129D    Altcode:
  Techniques currently used in the analysis of X-ray and UV spectroscopic
  data on solar features are reviewed with particular emphasis on
  those used for studies of active regions in the transition zone
  and corona. Attention is given to temperature and emission measure
  diagnostics by the use of line emission from a low-density plasma,
  broadband X-ray diagnostics, and diagnostics specific to various
  active region structures, and to electron density diagnostics based
  on metastable levels and the ratio of emission measure to the volume
  derived from spatially resolved images. Methods used for calculating
  atomic structure, electron and proton scattering, the ionization
  equilibrium and the effects on it of diffusion and flows, and the line
  profiles and optical depths are also considered.

---------------------------------------------------------
Title: Analysis and Interpretation of EUV Emission from Solar
    Active Regions
Authors: Dere, K. P.
1980BAAS...12..908D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Density and Temperature Measurements for Short Lived Transition
    Zone Phenomena
Authors: Nicolas, K. R.; Dere, K. P.; Bartoe, J. -D. F.; Brueckner,
   G. E.
1980BAAS...12R.530N    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Transient Plasmas in the Solar Transition Zone
Authors: Dere, K. P.; Nicolas, K. R.; Brueckner, G. E.
1980BAAS...12R.518D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The thermal X-ray flare plasma
Authors: Moore, R.; McKenzie, D. L.; Svestka, Z.; Widing, K. G.; Dere,
   K. P.; Antiochos, S. K.; Dodson-Prince, H. W.; Hiei, E.; Krall, K. R.;
   Krieger, A. S.
1980sfsl.work..341M    Altcode: 1980sofl.symp..341M
  Following a review of current observational and theoretical knowledge
  of the approximately 10 to the 7th K plasma emitting the thermal soft
  X-ray bursts accompanying every H alpha solar flare, the fundamental
  physical problem of the plasma, namely the formation and evolution of
  the observed X-ray arches, is examined. Extensive Skylab observations
  of the thermal X-ray plasmas in two large flares, a large subflare and
  several compact subflares are analyzed to determine plasma physical
  properties, deduce the dominant physical processes governing the plasma
  and compare large and small flare characteristics. Results indicate
  the density of the thermal X-ray plasma to be higher than previously
  thought (from 10 to the 10th to 10 to the 12th/cu cm for large to
  small flares), cooling to occur radiatively as much as conductively,
  heating to continue into the decay phase of large flares, and the
  mass of the thermal X-ray plasma to be supplied primarily through
  chromospheric evaporation. Implications of the results for the basic
  flare mechanism are indicated.

---------------------------------------------------------
Title: The Extreme Ultraviolet Structure of Solar Active Regions.
Authors: Dere, K. P.
1980PhDT.........2D    Altcode:
  The extreme ultraviolet emissions from solar active regions have
  been analyzed to determine their temperatures, densities, pressures,
  emission measures, flow velocities and structures. The accuracy and
  limitations of the diagnostic techniques are discussed. It is found
  that the active region structures are well correlated with the inferred
  and observed magnetic fields and that the electron pressure of the
  plasma is essentially constant over a wide range of temperatures. Cool
  (10('5)K (LESSTHEQ) T (LESSTHEQ) 10('6)K) loop structures are shon to be
  composed of unresolved filaments. Static and steady flow one dimensional
  hydrodynamical models of active region loops have been constructed and
  used to interpret the observations. Both models require a loop cross
  section that diverges with height. This is found by comparing the
  static model with the observed emission measures and the steady flow
  model with the observed flow velocities. No local heating is found to
  be needed in the transition zone. Transition zone downflows in active
  regions indicate a mass loss from the overlying coronal structures
  for which there is no know supply.

---------------------------------------------------------
Title: Radiative energy output of the 5 September 1973 flare
Authors: Canfield, R. C.; Cheng, C. -C.; Dere, K. P.; Dulk, G. A.;
   McLean, D. J.; Schmahl, E. J.; Robinson, R. D., Jr.; Schoolman, S. A.
1980sfsl.work..451C    Altcode: 1980sofl.symp..451C
  Measurements of the radiative energy output of the solar flare of
  Sept. 5, 1973, over a wavelength range of more than ten decades,
  from below 1 A to above 1 m are presented. Observations of soft
  X-rays (0.5-20 A), XUV and EUV lines (171-1863 A) and EUV continua
  (1400-1960 A), H alpha radiation, visible lines and continua (3700-8700
  A) and radio emission (centimeter to meter wavelengths) were obtained
  concurrently by Skylab and ground-based instruments. Estimates of power
  output at flare maximum are obtained for the observed wavelengths with
  uncertainty of at least half an order of magnitude, due to corresponding
  uncertainties in EUV and visible fluxes. Taking into account energy
  radiated at unobserved wavelengths and the characteristic time of
  the best-reduced data (the soft X-ray), calculations indicate a total
  radiated flare energy of approximately 4 x 10 to the 29th erg.

---------------------------------------------------------
Title: Mass Flow and Energy Balance in a Solar Flare
Authors: Cook, J. W.; Dere, K. P.
1979BAAS...11..678C    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: XUV electron density diagnostics for solar flares.
Authors: Dere, K. P.; Mason, H. E.; Widing, K. G.; Bhatia, A. K.
1979ApJS...40..341D    Altcode:
  Potential electron-density diagnostics for the high-temperature
  component of solar flares are studied with reference to the wavelength
  region from 171 to 630 A. The specific ions discussed include Fe
  IX through Fe XV, Ni XI through Ni XVII, and ions in the beryllium,
  boron, carbon, and nitrogen isoelectronic sequences. Line ratios that
  could be useful as density indicators under solar-flare conditions
  are indicated, available data for the ions considered are reviewed,
  and several theoretical intensity ratios are plotted. The results are
  employed to determine the electron-density distribution as a function
  of electron temperature for several spectra from two flares. For these
  flares it is found that the electron density increases from 10 billion
  to 500 billion per cu cm for a temperature increase from 1 million to
  10 million K.

---------------------------------------------------------
Title: The decay of the 1973 August 9 flare.
Authors: Dere, K. P.; Cook, J. W.
1979ApJ...229..772D    Altcode:
  The state and evolution of the decay-phase plasma from a compact solar
  flare that occurred on August 9, 1973, are investigated on the basis of
  XUV and X-ray observations from Skylab and Solrad 9. Density-sensitive
  line ratios are used to determine the electron density over the
  temperature range from 30,000 to 5 million K, and the differential
  emission measure in the temperature interval from 30,000 to 20 million
  K is derived for several times in the decay phase. The morphology of the
  flare is discussed, including its relation to the observed photospheric
  magnetic field. The sequential formation of new loops during the decay
  phase is emphasized as an essential element for understanding the
  decay phase of the flare. This idea is developed further by comparing
  the observed differential emission measure with that predicted by
  a semiempirical model which considers the sequential formation of
  isothermal loops that cool by radiation and thermal conduction.

---------------------------------------------------------
Title: Errors in Differential Emission Measure Solutions
Authors: Dere, K. P.
1978A&A....70..439D    Altcode:
  Summary. The possible errors in differential emission measures
  derived from spectral line intensities of limited accuracy have been
  examined by direct numerical simulation. The results indicate that if a
  functional form that is smooth and non-negative is used to approximate
  the differential emission measure, it is possible to obtain solutions
  which have errors that are not significantly greater than the errors
  in the spectral data. Key words: X-ray - XUV - spectra-plasmas

---------------------------------------------------------
Title: Evolution of the coronal and transition-zone plasma in a
compact flare: the event of 1973 August 9.
Authors: Underwood, J. H.; Antiochos, S. K.; Feldman, U.; Dere, K. P.
1978ApJ...224.1017U    Altcode:
  X-ray and extreme ultraviolet observations of a compact flare were
  analyzed to determine the relative importance of radiation, thermal
  conduction, and 'evaporation' in the evolution of the temperature and
  density structure of the plasma. In the event studied (1973 August 9),
  the electron density was relatively high (5 x 10 to the eleventh to 1 x
  10 to the twelfth) and radiation was evidently an important energy-loss
  and cooling mechanism. The light curves of ultraviolet lines formed at
  temperatures between 10 to the fifth to 10 to the seventh K indicate a
  time-varying emission measure gradient, and hence temperature gradient,
  during the flare. Radiative instability evidently played an important
  role in determining the steepness of these gradients during the rise
  and fall phases, and caused strong downward motions of material during
  the cooling phase. Toward the end of the event, the coronal electron
  density decreased and the temperature gradient relaxed toward that
  expected from a conduction-dominated plasma. For this flare, evaporative
  cooling did not appear to be a significant factor.

---------------------------------------------------------
Title: Spectral lines observed in solar flares between 171 and
    630 Angstroms.
Authors: Dere, K. P.
1978ApJ...221.1062D    Altcode:
  Several hundred spectral lines emitted in solar flares between
  171 and 630 A have been recorded by the Naval Research Laboratory
  spectroheliograph aboard Skylab. The wavelengths, identifications, and
  intensity estimates of these lines are presented, based on measurements
  of all of the suitable flare plates. Nearly 100 new and unidentified
  lines have been observed. Identifications of three Fe XXI and two Fe
  XVII lines are suggested.

---------------------------------------------------------
Title: EUV Observations of a Solar Active Region
Authors: Dere, K. P.
1978BAAS...10..440D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Multiple loop activation and continuous energy release in
    the solar flare of June 15, 1973.
Authors: Widing, K. G.; Dere, K. P.
1977SoPh...55..431W    Altcode:
  The spatial and temporal evolution of the high temperature plasma
  in the flare of 1973 June 15 has been studied using the flare images
  photographed by the NRL XUV spectroheliograph on Skylab.

---------------------------------------------------------
Title: Structure and dynamics of a solar flare: X-ray and XUV
    observations.
Authors: Dere, K. P.; Horan, D. M.; Kreplin, R. W.
1977ApJ...217..976D    Altcode:
  Results are presented for an analysis of X-ray and XUV emission from
  the solar flare that occurred on September 5, 1973. X-ray emission
  was monitored by ionization chambers aboard the Solrad 9 satellite,
  and the XUV emission in the wavelength range 170-345 A was recorded
  by a slitless objective-grating spectroheliograph on Skylab. The
  physical parameters of the flare plasma, including temperature, density,
  volume, and magnetic-field configuration, are evaluated. A geometrical
  loop model is used to determine the volumes of the various emitting
  regions. The structure of the flare in the rise and decay phases
  is examined in detail, and conclusions about the effect of various
  dynamic processes in the flare plasma are made. A major finding is
  that continued energy release is required well into the flare decay
  phase. In the rise phase, energy is apparently released only along a
  small portion of a loop, and in the decay phase apparently throughout
  most of its length.

---------------------------------------------------------
Title: Electron densities in solar flares from line ratios of Ca XVII.
Authors: Doschek, G. A.; Feldman, U.; Dere, K. P.
1977A&A....60L..11D    Altcode:
  Summary. We show that the intensity ratios of certain extreme
  ultraviolet spectral lines of Ca XVII are sensitive to electron density
  in solar flares. Calculations of the line ratios as functions of
  density are presented. These calculations are based on published atomic
  data for Ca XVII and for other ions of the beryllium isoelectronic
  sequence. For a flare that occurred on 9 August 1973, we derive a
  density of about 5 x 101 from the Ca XVII line ratios. Key words:
  solar flares - Be I sequence

---------------------------------------------------------
Title: The Solar Spectrum Below 10Å
Authors: Kreplin, R. W.; Dere, K. P.; Horan, D. M.; Meekins, J. F.
1977soiv.conf..287K    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Forbidden lines of highly ionized iron in solar flare spectra.
Authors: Doschek, G. A.; Feldman, U.; Dere, K. P.; Sandlin, G. D.;
   Vanhoosier, M. E.; Brueckner, G. E.; Purcell, J. D.; Tousey, R.
1975ApJ...196L..83D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: A Multi-Thremal Analysis of Solar X-Ray Emission
Authors: Dere, Kenneth P.; Horan, Donald M.; Kreplin, Robert W.
1974SoPh...36..459D    Altcode:
  The NRL SOLRAD 10 satellite carries six ionization chambers to measure
  solar X-radiation in the 0.5 to 60 Å wavelength band. The X-ray
  emission spectrum in this range is determined by the derivative of
  the coronal emission measure (∫ N<SUB>e</SUB><SUP>2</SUP>dV) with
  respect to temperature when the thermal processes of bremsstrahlung,
  radiative recombination and line radiation are considered. If a simple
  model for this differential emission measure is used and detector
  responses to the calculated spectra are fitted to the SOLRAD data
  by a least squares method, the differential emission measure can
  be obtained for temperatures between 2 × 10<SUP>6</SUP>K and 64 ×
  10<SUP>6</SUP>K. Data during quiet and flaring periods are analyzed and
  the general behavior of the differential emission measure during flares
  is presented. This analysis is based on experimental measurements of
  the efficiencies of the SOLRAD detectors.

---------------------------------------------------------
Title: The spectral dependence of solar soft X-ray flux values
    obtained by SOLRAD 9.
Authors: Dere, K. P.; Horan, D. M.; Kreplin, R. W.
1974JATP...36..989D    Altcode:
  The determination of solar energy flux values from ionization chamber
  experiments is discussed. Procedures and calculations necessary
  for the correction of SOLRAD 9 0.5-3 Å and 1-8 Å data and for the
  determination of the flare plasma temperature and emission measure
  are presented. These calculations are based on the continuum spectrum
  of CULHANE (1969), the line spectrum of TUCKER and KOREN (1971),
  and experimental values of the detector efficiencies.

---------------------------------------------------------
Title: Electron temperature and emission measure variations in the
    solar corona.
Authors: Horan, D. M.; Dere, K. P.; Kreplin, R. W.
1974spre.conf..441H    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Reduction of solar X-ray flux measurements for use in
    ionospheric research.
Authors: Kreplin, R. W.; Horan, D. M.; Dere, K. P.
1973spre.conf..469K    Altcode: 1973spre....1..469K
  No abstract at ADS