explanation      blue bibcodes open ADS page with paths to full text
Author name code: brynildsen
ADS astronomy entries on 2022-09-14
author:"Brynildsen, Nils" 

---------------------------------------------------------
Title: Dual Flows with Supersonic Velocities in the Sunspot Transition
    Region
Authors: Brynildsen, N.; Maltby, P.; Kjeldseth-Moe, O.; Wilhelm, K.
2004ApJ...612.1193B    Altcode:
  Observations of sunspot transition region lines that deviate
  significantly from a Gaussian shape are presented. Attention is given
  to “dual flows,” a line profile phenomenon in which two distinct
  velocities are observed within the same spatial resolution element. In
  5 out of 12 sunspots we observe dual flows. Several emission line
  profiles are well represented by two Gaussian line components, one
  with a subsonic and one with a supersonic line-of-sight velocity.

---------------------------------------------------------
Title: Oscillations in the Umbral Atmosphere
Authors: Brynildsen, N.; Maltby, P.; Foley, C. R.; Fredvik, T.;
   Kjeldseth-Moe, O.
2004SoPh..221..237B    Altcode:
  The results of simultaneous observations of oscillations in the
  chromosphere, transition region, and corona above nine sunspots are
  presented. The data are obtained through coordinated observing with the
  Solar and Heliospheric Observatory — SOHO and the Transition Region
  And Coronal Explorer — TRACE. Oscillations are detected above each
  umbra. The power spectra show one dominant frequency corresponding to
  a period close to 3 min. We show that the oscillations in the sunspot
  transition region can be modeled by upwardly propagating acoustic
  waves. In the corona the oscillations are limited to small regions that
  often coincide with the endpoints of sunspot coronal loops. Spectral
  observations show that oscillations in the corona contribute to the
  observed oscillations in the TRACE 171 Å channel observations. We
  show that a recent suggestion regarding a connection between sunspot
  plumes and 3-min oscillations conflicts with the observations.

---------------------------------------------------------
Title: Oscillations Above the Umbra of Sunspots
Authors: Brynildsen, N.; Maltby, P.; Fredvik, T.; Kjeldseth-Moe, O.
2004ESASP.547...45B    Altcode: 2004soho...13...45B
  Oscillations above thirteen sunspots are investigated with the Coronal
  Diagnostic Spectrometer (CDS) and the Transition Region And Coronal
  Explorer (TRACE). The CDS observations give knowledge about the
  oscillations in the chromosphere, transition region, and corona and
  information regarding the contributions of different emission lines to
  the TRACE 171 Å and 195 Å channel intensities. A period close to 3
  min is observed above the umbra of each sunspot. The observations give
  support to the idea that the 3 min oscillations are caused by upwardly
  propagating acoustic waves. This is evident from the asymmetry of
  the oscillation amplitudes in the red and blue wings of the emission
  lines, where the oscillations are decidedly more pronounced in the
  blue than in the red line wing. Additional support for the acoustic
  wave hypothesis emerges from the agreement between the observed and
  predicted relations in phase and magnitude between the oscillations in
  intensity and line-ofsight velocity. The frequency of the oscillations
  is above the acoustic cutoff frequency in the umbral atmosphere and
  the observed phase differences between lines emitting at different
  temperatures point to an upwardly propagating disturbance.

---------------------------------------------------------
Title: Search for a chromospheric resonator above sunspots
Authors: Brynildsen, N.; Maltby, P.; Brekke, P.; Redvik, T.;
   Kjeldseth-Moe, O.
2003AdSpR..32.1097B    Altcode:
  We have recently observed thirteen sunspots, both with CDS on SOHO
  and TRACE. For each sunspot we investigate the oscillations in the
  chromosphere, transition region and corona. Above the umbra the
  power spectra show one dominant peak corresponding to a period of 3
  minutes. The intensity oscillation amplitude increases with increasing
  temperature, reaches a maximum for lines emitting close to 1-2 ×
  10 <SUP>5</SUP> K, and decreases for higher temperatures. Part of
  the wave energy penetrates into the corona, channeled into small
  areas that appear to coincide with the endpoints of sunspot coronal
  loops. The observations support the hypothesis that the oscillations
  are caused by upwardly propagating acoustic waves and show no signs
  of the resonances, equally spaced ≈1 mHz in frequency, predicted by
  the chromospheric resonator theories.

---------------------------------------------------------
Title: Sunspot Oscillations and Acoustic Wave Propagation
Authors: Brekke, P.; Brynildsen, N.; Maltby, P.; Fredvik, T.;
   Kjeldseth-Moe, O.
2003SPD....34.0401B    Altcode: 2003BAAS...35..810B
  Observations with the Coronal Diagnostic Spectrometer of 3 min
  oscillations in sunspot umbrae support the hypothesis that they are
  caused by upwardly propagating acoustic waves. This is evident from
  the asymmetry of oscillation amplitudes in the red and blue wings of
  spectral lines, where the oscillations are decidedly more pronounced
  in the blue than in the red line wing. Additional evidence include the
  fact that the relation between oscillations in intensity and velocity
  agree with that predicted for an acoustic wave with regard to phase
  as well as magnitude. Finally, the observed phase difference between
  lines formed at different temperatures points to an upward propagating
  disturbance, and the value of dominant frequency of the oscillations,
  close to 6 mHz, is above the acoustic cutoff frequency in the sunspot
  atmosphere. SOHO is a mission of international cooperation between ESA
  and NASA. This study was supported by the Research Council of Norway.

---------------------------------------------------------
Title: Oscillations in the wings of sunspot transition region lines
Authors: Brynildsen, N.; Maltby, P.; Kjeldseth-Moe, O.; Wilhelm, K.
2003A&A...398L..15B    Altcode:
  We explore a new approach to the investigation of optically thin
  emission lines by comparing the intensity variations in opposite
  wings of the spectral lines and apply the method to investigate the
  oscillations above sunspots. The observations show that it is easier to
  detect the 3 min oscillations above sunspots in the short wavelength
  (“blue”) wing than in the long wavelength (“red”) wing of the
  lines. The observed oscillations are compatible with the spectral line
  signatures of upwardly propagating acoustic waves.

---------------------------------------------------------
Title: Sunspot oscillations in the chromosphere, transition region,
    and corona
Authors: Brynildsen, N.; Maltby, P.; Fredvik, T.; Kjeldseth-Moe, O.
2002ESASP.506..513B    Altcode: 2002ESPM...10..513B; 2002svco.conf..513B
  The results of simultaneous observations with CDS on SOHO and TRACE
  for thirteen sunspots in 2001 and 2002 are combined with previous
  results for six sunspots observed with CDS and SUMER on SOHO. Intensity
  oscillations are detected above each umbra and spectral observations
  of chromospheric and transition region lines allow us to measure
  oscillations in the line-of-sight velocity in several sunspots. The
  power spectra show one dominant peak close to 6 mHz, corresponding
  to a period of 3 minutes. The oscillation amplitude increases with
  increasing temperature, reaches a maximum for lines emitting close
  to 1-2×10<SUP>5</SUP>K, and decreases for higher temperatures. Part
  of the wave energy penetrates into the corona, channeled into small
  areas that appear to coincide with the endpoints of sunspot coronal
  lops. The observations support the hypothesis that the oscillations
  are caused by upwardly propagating acoustic waves. The observations
  are not compatible with the concept of a chromospheric resonator.

---------------------------------------------------------
Title: On the nature of the 3 minute oscillations above sunspots
Authors: Hansteen, V. H.; Wikstøl, Ø.; Brynildsen, N.; Maltby, P.;
   Fredvik, T.; Kjeldseth-Moe, O.
2002ESASP.505..183H    Altcode: 2002IAUCo.188..183H; 2002solm.conf..183H
  Oscillations in the sunspot transition region and corona are observed
  simultaneously with the Coronal Diagnostic Spectrometer - CDS on SOHO
  and the Transition Region And Coronal Explorer - TRACE. Observations
  of thirteen sunspots in 2001 and 2002 show that the amplitude in
  the relative integrated line intensity increases with increasing
  temperature, reaches a maximum for emission lines formed close to
  1-2×10<SUP>5</SUP>K, and decreases at higher temperatures. Part of the
  wave energy penetrates into the corona, channeled into small areas that
  appear to coincide with the endpoints of sunspot coronal loops. The
  observed power spectra show one dominating peak close to 6 mHz. To
  explore the nature of the waves we calculate upwardly propagating
  acoustic waves confined to a magnetic flux tube and compare the results
  with the observations.

---------------------------------------------------------
Title: Oscillations Above Sunspots
Authors: Brynildsen, N.; Maltby, P.; Fredvik, T.; Kjeldseth-Moe, O.
2002SoPh..207..259B    Altcode:
  The 3-min oscillations in the sunspot atmosphere are discussed, based
  on joint observing with the Transition Region and Coronal Explorer -
  TRACE and the Solar and Heliospheric Observatory - SOHO. We find that
  the oscillation amplitude above the umbra increases with increasing
  temperature, reaches a maximum for emission lines formed close to 1-2×
  10<SUP>5</SUP> K, and decreases for higher temperatures. Oscillations
  observed with a high signal-to-noise ratio show deviations from pure
  linear oscillations. The results do not support the sunspot filter
  theory, based on the idea of a chromospheric resonator. Whereas the
  filter theory predicts several resonant peaks in the power spectra,
  equally spaced ∼ 1 mHz in frequency, the observed power spectra show
  one dominating peak, close to 6 mHz. Spectral observations show that the
  transition region lines contribute less than 13 percent to the TRACE 171
  Å channel intensity above the umbra. The 3-min oscillations fill the
  sunspot umbra in the transition region. In the corona the oscillations
  are concentrated to smaller regions that appear to coincide with the
  endpoints of sunspot coronal loops, suggesting that wave propagation
  along the magnetic field makes it possible for the oscillations to
  reach the corona.

---------------------------------------------------------
Title: 3 minute oscillations above sunspots
Authors: Brynildsen, N.; Maltby, P.; Fredvik, T.; Kjeldseth-Moe, O.
2002ESASP.508..283B    Altcode: 2002soho...11..283B
  The aim of this investigation is a better understanding of the 3 minute
  oscillations above sunspots. We present the first results from a joint
  observing programme with SOHO and TRACE. Attention is given to the wave
  amplitude as a function of the temperature and to the penetration of
  part of the wave energy into the corona. The results appear to disagree
  with the sunspot filter theory.

---------------------------------------------------------
Title: The 6 mHz Oscillations above Sunspots
Authors: Brekke, P.; Brynildsen, N.; Maltby, P.; Fredvik, T.;
   Kjeldseth-Moe, O.
2002AAS...200.8806B    Altcode: 2002BAAS...34..790B
  Sunspot oscillations in the transition region and corona are observed
  simultaneously with CDS on SOHO and TRACE. Results obtained from
  investigations of ten sunspots in 2001 and 2002 are presented. We
  find that the oscillation amplitude above the umbra increases with
  increasing temperature, reaches a maximum for lines emitted close to 200
  000 K, and decreases for higher temperatures. Part of the wave energy
  penetrates into the corona, channeled into small areas that appear
  to coincide with the endpoints of sunspot coronal loops. The observed
  power spectra show one dominating peak, near 6 mHz, and not several,
  equally spaced resonances as predicted by theories based on the idea
  of a chromospheric resonator. We conclude that the observations are
  compatible with upwardly propagating acoustic waves.

---------------------------------------------------------
Title: Redshift in sunspot plumes
Authors: Brynildsen, N.; Maltby, P.; Kjeldseth-Moe, O.
2002AdSpR..30..529B    Altcode:
  The non-uniform spatial distributions of emission and wavelength
  shift in ten EUV lines formed in the chromosphere, transition region
  and corona above 50 sunspots are investigated, based on observations
  with the Coronal Diagnostic Spectrometer on the Solar and Heliospheric
  Observatory. The sunspot plumes are the most prominent features in the
  transition region line emissions. We find that almost all sunspots
  show a plume when one magnetic polarity dominates the region out
  to a distance of 50″ from the sunspot. Both the enhanced emission
  and the redshift in sunspot plumes increase with the line formation
  temperature, T, reach a maximum close to log T = 5.5 and cease to
  exist close to log T = 6.0. The mass flow in the corona is too small
  to explain the observed redshift in the transition region. We present
  a working hypothesis where gas at transition region temperatures moves
  in flow channels from the surroundings into the sunspot.

---------------------------------------------------------
Title: Search for a chromospheric resonator above sunspots
Authors: Brynildsen, N.; Maltby, P.; Brekke, P.; Fredvik, T.;
   Kjeldseth-Moe, O.
2002cosp...34E.178B    Altcode: 2002cosp.meetE.178B
  We have recently observed eleven sunspots, both with CDS on SOHO
  and TRACE as part of our on-going investigations of the sunspot
  atmosphere. For each sunspot we investigate the oscillations in
  the chromosphere, transition region and corona. The observed power
  spectra show one dominating peak corresponding to a period of 3
  minutes. The oscillation amplitude above the umbra increases with
  increasing temperature, reaches a maximum for lines emitting close to
  200 000 K, and decreases for higher temperatures. Part of the wave
  energy penetrates into the corona, channeled into small areas that
  appear to coincide with the endpoints of sunspot coronal loops. The
  observations support the hypothesis that the oscillations are caused
  by upwardly propagating acoustic waves and show no signs of equally
  spaced resonances as predicted by theories based on the idea of a
  chromospheric resonator.

---------------------------------------------------------
Title: Plumes and oscillations in the sunspot transition region
Authors: Maltby, P.; Brynildsen, N.; Kjeldseth-Moe, O.; Wilhelm, K.
2001A&A...373L...1M    Altcode:
  The suggestion that sunspot transition region oscillations are a typical
  feature of the sunspot plumes is examined. The present observations show
  3 min oscillations in the umbra that end at the umbral rim. We find
  that sunspot plumes located above the umbra show these oscillations,
  in contrast to plumes above the penumbra. These two findings suggest
  that the oscillations may be a property of the umbral transition region.

---------------------------------------------------------
Title: Dual Flows and Oscillations in the Sunspot Transition Region
Authors: Brynildsen, N.; Maltby, P.; Kjeldseth-Moe, O.; Wilhelm, K.
2001ApJ...552L..77B    Altcode:
  New knowledge about sunspot transition region lines that deviate
  significantly from a Gaussian shape are presented. Attention is given
  to “multiple flows,” a line profile phenomenon in which two or more
  distinct velocities are observed within the same spatial resolution
  element. We observe line profiles that are well represented by two
  Gaussian line components in the N V λ1242 and O V λ629 lines and
  introduce the notation “dual flow.” We have detected transition region
  oscillations in one of the line components in the dual-flow events.

---------------------------------------------------------
Title: Velocities in Sunspot Plumes
Authors: Maltby, P.; Kjeldseth-Moe, O.; Brynildsen, N.
2001IAUS..203..300M    Altcode:
  We investigate the line-of-sight velocities in 50 sunspot regions,
  based on observations of ten or six EUV emission lines with the
  Coronal Diagnostic Spectrometer - CDS on the Solar and Heliospheric
  Observatory - SOHO. The position of the sunspots on the solar disk
  ranges from disk centre to locations close to the solar limb. Attention
  is given to the sunspot plumes, the most prominent features in the
  transition region intensity maps. More than half of the sunspots
  show downflows in the sunspot plumes that exceed 25 km s<SUP>-1</SUP>
  at temperatures close to 300 000 K. The observations show that this
  downflow cannot be maintained by inflow from the corona. The downflow
  in the sunspot plumes appears to be maintained by gas at transition
  region temperatures, streaming in flow channels from locations well
  outside the sunspot. Although individual flow channels show significant
  changes during approximately 10 minutes, part of the velocity pattern
  remains unaltered for approximately one day. The velocity fields in
  the transition region and the chromosphere are compared and the siphon
  flow mechanism is confronted with the observations.

---------------------------------------------------------
Title: Sunspot Plumes and Flow Channels
Authors: Brynildsen, N.; Maltby, P.; Fredvik, T.; Kjeldseth-Moe, O.;
   Wilhelm, K.
2001SoPh..198...89B    Altcode:
  It is well known that sunspots are dark. This statement is not correct
  in the sunspot atmosphere between the chromosphere and the corona,
  where sunspots often are brighter than their surroundings. The brightest
  feature in the sunspot transition region is called a sunspot plume. Not
  all sunspots contain a plume. We find that 20 out of 21 sunspots show
  a plume when one magnetic polarity dominates the sunspot region out
  to a distance of 50 <SUP>”</SUP> from the sunspot. Most sunspots show
  downflows that exceed 25 km s<SUP>−1</SUP> in the sunspot plumes at
  temperatures close to 250 000 K. This downflow is not maintained by
  inflow from the corona, but by gas at transition region temperatures,
  streaming in flow channels from locations well outside the sunspot. We
  suggest that this inflow is a necessary requirement for the sunspot
  plume to occur and present a working hypothesis for the origin of
  sunspot plumes. This paper is the first thorough spectral analysis of
  sunspot plumes. It is based on simultaneous observations of ten or six
  EUV emission lines in 42 sunspot regions with the Coronal Diagnostic
  Spectrometer - CDS on the Solar and Heliospheric Observatory - SOHO. The
  line profiles are studied in detail with another SOHO instrument,
  the Solar Ultraviolet Measurements of Emitted Radiation - SUMER.

---------------------------------------------------------
Title: On Sunspot Plumes and Dynamics above Sunspot Regions (CD-ROM
Directory: contribs/brynild)
Authors: Brynildsen, N.; Maltby, P.; Kjeldseth-Moe, O.
2001ASPC..223..595B    Altcode: 2001csss...11..595B
  No abstract at ADS

---------------------------------------------------------
Title: Observations of sunspot transition region oscillations
Authors: Brynildsen, N.; Maltby, P.; Leifsen, T.; Kjeldseth-Moe, O.;
   Wilhelm, K.
2000SoPh..191..129B    Altcode:
  Oscillations with a period of 3 minutes are observed in the transition
  region of six sunspots with the Solar and Heliospheric Observatory
  - SOHO joint observing programme for velocity fields in sunspot
  regions. Observations of the transition region lines O v λ629
  and N v λλ1238, 1242 with the SUMER instrument show significant
  differences in the amplitude of the 3-minute oscillations from one
  sunspot to another, both in intensity and line-of-sight velocity. In
  four sunspots the central part of the umbra is observed. Two of these
  sunspots show coincidence between the maxima in peak line intensity
  and velocity directed towards the observer, as is expected for an
  upward-propagating acoustic wave. The two other sunspots show large
  oscillation amplitudes and a difference of 25° between maxima in
  intensity and blue shift. The possible effect of partial wave reflection
  on the observed phase relation is discussed. For one sunspot only a part
  of the umbra, close to the penumbra, was observed and the observations
  show a difference of 50° between maxima in intensity and blueshift. For
  the smallest sunspot the observations are found to be contaminated by
  contributions from an area without oscillations. Observed oscillations
  in line width are small, but probably significant in two sunspots. The
  observations of NOAA 8378 allow us to compare simultaneous recordings
  of the oscillations in the chromospheric Si ii λ1260 line with the
  oscillations in the transition region lines. We question the suggestion
  by Fludra (1999) that the sunspot transition region oscillations are
  a typical feature of the sunspot plumes.

---------------------------------------------------------
Title: Dynamics in Restructuring Active Regions Observed During
    Soho/Yohkoh/Gbo Campaigns
Authors: Schmieder, B.; Deng, Y.; Mandrini, C. H.; Rudawy, P.; Nitta,
   N.; Mason, H.; Fletcher, L.; Martens, P.; Brynildsen, N.
2000AdSpR..25.1879S    Altcode:
  JOP17 and JOP 33 are SOHO Joint Observing Programs in collaboration
  with Yohkoh/SXT and ground based observatories (GBO's), dedicated to
  observe dynamical events through the atmosphere. During runs of these
  programs we observed in restructuring active regions (ARs), surges,
  subflares, bright knots, but not large flares and jets. From these
  observations we have been able to derive some of the responses of the
  coronal and chromospheric plasma to the evolution of the photospheric
  magnetic field. Emerging flux in an AR led to the formation of Arch
  Filament Systems in the chromosphere, hot loops and knots in the
  transition region, and X-ray loops. Frequent surges have been observed
  in relation to parasitic or mixed polarities, but coronal jets have not
  yet been found. We discuss the possible mechanisms acting during the
  restructuring of the active regions (reconnection or “sea-serpent”
  geometries)

---------------------------------------------------------
Title: Signatures of Magnetic Reconnection and Observed EUV Emission
    Line Profiles in An Active Region
Authors: Brekke, P.; Brynildsen, N.; Kjeldseth-Moe, O.; Maltby, P.;
   Wilhelm, K.
2000AdSpR..26..457B    Altcode:
  We report on observations with SUMER on SOHO of high-velocity events,
  also called explosive events. The high spatial and spectral resolutions
  of SUMER allow simultaneous observations of EUV emission lines formed
  at different temperatures within the transition region. Complex
  line profiles with three separate line components appear to be
  a characteristic feature of many high-velocity events based on a
  survey of Si IV λ1393 observations. The present study is based on
  551 spectra of the active region NOAA 7995 obtained on 17 November
  1996. We find that the complex line profiles of explosive events may be
  represented by a composite line profile consisting of three Gaussian
  line components. Both positive and negative line-of-sight velocities
  are found to be significantly larger at 6.3 ×10<SUP>5</SUP> K than
  at 1.5 - 1.7 ×10<SUP>5</SUP> K. We briefly confront the observations
  with signatures predicted from magnetic reconnections, disturbances
  originating in the corona and flows in an extremely structured
  transition region

---------------------------------------------------------
Title: Structure and Dynamics in the Atmosphere Above Sunspot Regions
Authors: Brynildsen, N.; Brekke, P.; Haugan, S. V. H.; Kjeldseth-Moe,
   O.; Maltby, P.; Wikstøl, Ø.
2000AdSpR..25.1743B    Altcode:
  Based on simultaneous observations of 10 EUV emission lines with the
  Coronal Diagnostic Spectrometer - CDS on the Solar and Heliospheric
  Observatory - SOHO we study the spatial distributions of both line
  emission and line-of-sight velocity in the atmosphere above 17
  sunspots. We find that both the enhanced EUV line emissions and the
  velocities are distributed non-uniformly over the sunspot regions. Areas
  with enhanced line emission tend to be red shifted, but they seldom
  coincide exactly with areas with enhanced velocity. Bright sunspot
  plumes with motion directed away from the observer are observed in
  most of the sunspot regions

---------------------------------------------------------
Title: On the sunspot transition region
Authors: Maltby, P.; Brynildsen, N.; Fredvik, T.; Kjeldseth-Moe, O.;
   Wilhelm, K.
1999SoPh..190..437M    Altcode:
  The EUV line emission and relative line-of-sight velocity in the
  transition region between the chromosphere and corona of 36 sunspot
  regions are investigated, based on observations with the Coronal
  Diagnostic Spectrometer - CDS and the Solar Ultraviolet Measurements of
  Emitted Radiation - SUMER on the Solar and Heliospheric Observatory -
  SOHO. The most prominent features in the transition-region intensity
  maps are the sunspot plumes. In the temperature range between log T=5.2
  and log T=5.6 we find that 29 of the 36 sunspots contain one or two
  sunspot plumes. The relative line-of-sight velocity in sunspot plumes
  is high and directed into the Sun in the transition region, for 19 of
  the sunspots the maximum velocity exceeds 25 km s<SUP>−1</SUP>. The
  velocity increases with increasing temperature, reaches a maximum
  close to log T=5.5 and then decreases abruptly.

---------------------------------------------------------
Title: EUV Line Emission and Dynamics in Sunspot Regions
Authors: Brynildsen, N.; Maltby, P.; Kjeldseth-Moe, O.
1999ESASP.446..201B    Altcode: 1999soho....8..201B
  The spatial distributions of EUV line emission and relative
  line-of-sight velocity in the atmosphere above 22 sunspot regions are
  investigated. The study is based on simultaneous observations of ten
  EUV emission lines with the Coronal Diagnostic Spectrometer -- CDS on
  SOHO. Since the EUV emission lines are formed at different temperatures,
  we study the sunspot atmosphere from the chromosphere to the corona. We
  observe both a rapid variation with a characteristic time of a few to
  several minutes and a slow variation with a time constant of several
  hours to approximately one day. The sunspot plume concept is reinvented
  to describe the most prominent emission feature in the intensity maps in
  the temperature range log T approx 5.2 - 5.6. The relative line-of-sight
  velocity in sunspot plumes is high and directed into the Sun in the
  transition region. The flow is maintained by plasmas at transition
  region temperatures, moving from regions located at greater heights
  outside the sunspot and towards the sunspot. Only a few features show
  the signatures of a siphon flow. Comparisons of intensity and velocity
  maps suggest that gas at transition region temperatures occur in loops
  different from loops with coronal temperatures. However, we cannot
  exclude the presence of transition region temperatures close to the
  footpoints of flux tubes emitting at coronal temperatures.

---------------------------------------------------------
Title: Sunspot Transition Region Oscillations
Authors: Brynildsen, N.; Kjeldseth-Moe, O.; Maltby, P.; Wilhelm, K.
1999ESASP.446..207B    Altcode: 1999soho....8..207B
  Based on the SOHO joint observing programme for velocity fields in
  sunspots, we have detected 3 min transition region umbral oscillations
  in six sunspots. Simultaneous recordings of O V lambda 629, NV lambdas
  1238, 1242 and Si I lambda 1260 with the SUMER instrument allow us to
  compare the transition region oscillations with the 3 min chromospheric
  oscillations above the sunspot. We investigate the amplitudes and phase
  relations of the oscillations in peak line intensity, line-of-sight
  velocity and line width. The spatial distributions of power in the
  3 min oscillations, both in intensity and line-of-sight velocity,
  are presented. The observations show that the maxima in peak line
  intensity are nearly, but not exactly in phase with the maxima in
  velocity directed towards the observer. The suggestion that the waves
  are upward propagating acoustic waves is confronted with observations.

---------------------------------------------------------
Title: EUV Observations of Sunspot Regions with CDS on SOHO
Authors: Brynildsen, N.; Brekke, P.; Haugan, S. V. H.; Kjeldseth-Moe,
   O.; Maltby, P.
1999ASPC..184..266B    Altcode:
  The spatial distributions of line emission and line-of-sight velocity in
  seventeen different sunspot regions are studied, based on observations
  with the Coronal Diagnostic Spectrometer - CDS on SOHO. Ten EUV emission
  lines, formed in the chromosphere, transition region, and corona are
  observed. Enhanced EUV line emissions in the transition region are
  distributed non-uniformly over the active regions and are located both
  inside and outside sunspots. Most sunspot regions show strongly enhanced
  transition region line emission above the spot, i.e. sunspot plumes
  are reinvented. From wavelength shifts we derive the line-of-sight
  velocity, relative to the average velocity in the rastered area, 120"
  x 120". In sunspot plumes we find that the motion is directed away from
  the observer and increases with increasing line formation temperature,
  T, reaches a maximum up to 40 km s<SUP>-1</SUP> close to log T ≅ 5.5,
  then decreases abruptly. The spatial extent of both emission features
  and flow regions increase with increasing temperature within the
  transition region. The observations show a marked difference between
  the transition region and the low corona, both regarding the spatial
  distributions of line emission and line-of-sight velocity.

---------------------------------------------------------
Title: Transition Region Oscillations in a Sunspot Region
Authors: Brynildsen, N.; Fredvik, T.; Kjeldseth-Moe, O.; Maltby, P.
1999ASPC..184..146B    Altcode:
  Umbral oscillations in the sunspot transition region have been detected
  and described from SOHO observations, mainly taken with SUMER of
  NOAA 8156 on 18 February 1998 between 16:00 UT and 21:07 UT. SUMER
  recorded simultaneously in the transition regions lines O V λ629, N
  V λ1238 and N V λ1242, combined with long exposures for wavelength
  calibration. Transition region oscillations with periods close to 3
  min were observed both in intensity and in line-of-sight velocity;
  the maximum intensity is nearly in phase with maximum velocity
  directed towards the observer. The wave characteristics appear to be
  compatible with the results of Gurman et al. (1982) from UVSP on SMM,
  who interpreted them as upward propagating acoustic waves.

---------------------------------------------------------
Title: Nonlinear Sunspot Transition Region Oscillations in NOAA 8378
Authors: Brynildsen, N.; Kjeldseth-Moe, O.; Maltby, P.; Wilhelm, K.
1999ApJ...517L.159B    Altcode:
  Observations obtained with the Solar and Heliospheric Observatory
  joint observing program for velocity fields in sunspot regions are
  used to study the 3 minute transition region oscillations above four
  sunspots. Here we report mainly on the results obtained for NOAA 8378,
  based on simultaneous recordings of the transition region lines O
  V λ629 and N V λλ1238, 1242 and the chromospheric Si II λ1260
  line with the Solar Ultraviolet Measurements of Emitted Radiation
  instrument. The 3 minute transition region oscillations in NOAA 8378
  occur mainly above the umbra and show (1) larger peak line intensity
  amplitudes than reported before, (2) clear signs of nonlinearities,
  (3) significant oscillations in line width, (4) maxima in peak line
  intensity and maxima in velocity directed toward the observer that
  are nearly, but not exactly in phase, and (5) a clear connection to
  the oscillations in the sunspot chromosphere. The suggestion that the
  waves are upward-propagating acoustic waves is confronted with the
  observations by a simple test.

---------------------------------------------------------
Title: SOHO Observations of the Structure and Dynamics of Sunspot
    Region Atmospheres
Authors: Brynildsen, N.; Maltby, P.; Brekke, P.; Haugan, S. V. H.;
   Kjeldseth-Moe, O.
1999SoPh..186..141B    Altcode:
  We present results from a study of the spatial distributions of line
  emission and relative line-of-sight velocity in the atmosphere above
  17 sunspot regions, from the chromosphere, through the transition
  region and into the corona, based on simultaneous observations of ten
  EUV emission lines with the Coronal Diagnostic Spectrometer - CDS on
  SOHO. We find that the spatial distributions are nonuniform over the
  sunspot region and introduce the notation 'sunspot loop' to describe an
  enhanced transition region emission feature that looks like a magnetic
  loop, extending from inside the sunspot to the surrounding regions. We
  find little evidence for the siphon flow. Attention is given to the time
  variations since we observe both a rapid variation with a characteristic
  time of a few to several minutes and a slow variation with a time
  constant of several hours to ≈ 1 day. The most prominent features
  in the transition region intensity maps are the sunspot plumes. We
  introduce an updated criterion for the presence of plumes and find
  that 15 out of 17 sunspots contain a plume in the temperature range
  logT≈5.2-5.6. The relative line-of-sight velocity in sunspot plumes
  is high and directed into the Sun in the transition region. Almost
  all the sunspot regions contain one or a few prominent, strongly
  redshifted velocity channels, several of the channels extend from the
  sunspot plume to considerable distances from the sunspot. The flow
  appears to be maintained by plasmas at transition region temperatures,
  moving from regions located at a greater height outside the sunspots
  and towards the sunspot. The spatial correlation is high to moderate
  between emission lines formed in the transition region lines, but
  low between the transition region lines and the coronal lines. From
  detailed comparisons of intensity and velocity maps we find transition
  region emission features without any sign of coronal emission in the
  vicinity. A possible explanation is that the emission originates in
  magnetic flux tubes that are too cold to emit coronal emission. The
  comparisons suggest that gas at transition region temperature occur in
  loops different from loops with coronal temperature. However, we cannot
  exclude the presence of transition region temperatures close to the
  footpoints of flux tubes emitting at coronal temperatures. Regions with
  enhanced transition region line emission tend to be redshifted, but the
  correlation between line emission and relative line-of-sight velocity
  is weak. We extend our conditional probability studies and confirm
  that there is a tendency for line profiles with large intensities and
  red shifts (blue shifts) above the average to constitute an increasing
  (decreasing) fraction of the profiles as the wavelength shift increases.

---------------------------------------------------------
Title: Sunspot Transition Region Oscillations in NOAA 8156
Authors: Brynildsen, N.; Leifsen, T.; Kjeldseth-Moe, O.; Maltby, P.;
   Wilhelm, K.
1999ApJ...511L.121B    Altcode: 1998astro.ph.12012B
  Based on observations obtained with the Solar and Heliospheric
  Observatory joint observing program for velocity fields in sunspot
  regions, we have detected 3 minute transition region umbral oscillations
  in NOAA 8156. Simultaneous recordings of O V λ629 and N V λ1238,
  λ1242 with the SUMER instrument give the spatial distribution of power
  in the 3 minute oscillations, both in intensity and in line-of-sight
  velocity. Comparing loci with the same phase, we find that the entire
  umbral transition region oscillates. The observed maxima in peak line
  intensity are nearly in phase with the maxima in velocity directed
  toward the observer. We discuss the suggestion that the waves are
  upward-propagating acoustic waves.

---------------------------------------------------------
Title: Flows in Sunspot Plumes Detected with SOHO
Authors: Brynildsen, N.; Maltby, P.; Brekke, P.; Fredvik, T.; Haugan,
   S. V. H.; Kjeldseth-Moe, O.; Wikstol, O.
1998ApJ...504L.135B    Altcode: 1998astro.ph..5249B
  In the Letter, “Flows in Sunspot Plumes Detected with the Solar and
  Heliospheric Observatory” by N. Brynildsen, P. Maltby, P. Brekke,
  T. Fredvik, S. V. H. Haugan, O. Kjeldseth-Moe, and Ø. Wikstøl (ApJ,
  502, L85 [1998]), the following correction should be made: <P />In
  the last line on page L86, which reads “peak line intensity I&gt;=5
  are located (1) above the umbra or, ” an “Ī” should be inserted so
  that the revised line reads “peak line intensity I&gt;=5Ī are located
  (1) above the umbra or.”

---------------------------------------------------------
Title: Flows in Sunspot Plumes Detected with the Solar and
    Heliospheric Observatory
Authors: Brynildsen, N.; Maltby, P.; Brekke, P.; Fredvik, T.; Haugan,
   S. V. H.; Kjeldseth-Moe, O.; Wikstøl, Ø.
1998ApJ...502L..85B    Altcode:
  Bright extreme-UV sunspot plumes have been observed in eight out of
  11 different sunspot regions with the Coronal Diagnostic Spectrometer
  on Solar and Heliospheric Observatory. From wavelength shifts, we
  derive the line-of-sight velocity relative to the average velocity
  in the rastered area, 120<SUP>”</SUP>×120<SUP>”</SUP>. In sunspot
  plumes, we find that the motion is directed away from the observer
  and increases with increasing line formation temperature, reaches a
  maximum between 15 and 41 km s<SUP>-1</SUP> close to log logT~5.5,
  then decreases abruptly. The flow field in the corona is not well
  correlated with the flow in the transition region, and we discuss
  briefly the implication of this finding.

---------------------------------------------------------
Title: SOHO Observations of the Connection Between Line Profile
    Parameters in Active and Quiet Regions and the Net Red Shift in EUV
    Emission Lines
Authors: Brynildsen, N.; Brekke, P.; Fredvik, T.; Haugan, S. V. H.;
   Kjeldseth-Moe, O.; Maltby, P.; Harrison, R. A.; Wilhelm, K.
1998SoPh..181...23B    Altcode:
  We present high spatial and spectral resolution observations of
  one active and one quiet-Sun region, obtained with CDS and SUMER on
  SOHO. The connections between the line profile parameters are studied
  and a systematic wavelength shift towards the red with increasing peak
  line intensity (line broadening) is detected. The large scatter in
  the data calls for another approach. We apply conditional probability
  analysis to a series of EUV emission lines and find significant
  correlations between line profile parameters. For a given interval in
  wavelength shift we find that: (1) line profiles with large intensities
  (line widths) and red shifts above the average constitute an increasing
  fraction of the profiles as the relative wavelength shift increases,
  (2) line profiles with large intensities (line widths) and blue
  shifts compared to the average, on the other hand, constitute a
  decreasing fraction of the profiles as the relative wavelength shift
  increases. These results extend the findings of an earlier quiet-Sun
  study from one to several emission lines and expand the validity to
  include the active region. Interestingly, the active region observations
  show correlations between peak line intensity and wavelength shift in
  the coronal lines.

---------------------------------------------------------
Title: EUV Spectroscopy of the Sunspot Region NOAA 7981 Using SOHO -
    II. Velocities and Line Profiles
Authors: Brynildsen, N.; Brekke, P.; Fredvik, T.; Haugan, S. V. H.;
   Kjeldseth-Moe, O.; Maltby, P.; Harrison, R. A.; Pike, C. D.; Rimmele,
   T.; Thompson, W. T.; Wilhelm, K.
1998SoPh..179..279B    Altcode:
  We have studied the dynamics in the sunspot transition region between
  the chromosphere and the corona and investigated the extension of
  the flow field into the corona. Based on EUV spectra of a medium size
  sunspot and its surroundings, NOAA 7981, observed with CDS and SUMER
  on SOHO, we derive line-of-sight velocities and study the line profiles
  for a series of emission lines.

---------------------------------------------------------
Title: Extreme-Ultraviolet Sunspot Plumes Observed with SOHO
Authors: Maltby, P.; Brynildsen, N.; Brekke, P.; Haugan, S. V. H.;
   Kjeldseth-Moe, O.; Wikstøl, Ø.; Rimmele, T.
1998ApJ...496L.117M    Altcode: 1998astro.ph..1144M
  Bright EUV sunspot plumes have been observed in five out of nine sunspot
  regions with the Coronal Diagnostic Spectrometer on the Solar and
  Heliospheric Observatory. In the other four regions, the brightest line
  emissions may appear inside the sunspot but are mainly concentrated in
  small regions outside the sunspot areas. These results are in contrast
  to those obtained during the Solar Maximum Mission but are compatible
  with the Skylab mission results. The present observations show that
  sunspot plumes are formed in the upper part of the transition region,
  occur in both magnetic unipolar and bipolar regions, and may extend
  from the umbra into the penumbra.

---------------------------------------------------------
Title: EUV Spectroscopy of the Sunspot Region NOAA 7981 Using SOHO -
    I. Line Emission and Time Dependence
Authors: Brynildsen, N.; Brekke, P.; Fredvik, T.; Haugan, S. V. H.;
   Kjeldseth-Moe, O.; Maltby, P.; Harrison, R. A.; Pike, C. D.; Rimmele,
   T.; Thompson, W. T.; Wilhelm, K.
1998SoPh..179...43B    Altcode:
  EUV spectra of a medium-size sunspot and its surroundings, NOAA 7981,
  were obtained on 2 August 1996 with the Coronal Diagnostic Spectrometer
  (CDS) and the Solar Ultraviolet Measurements of Emitted Radiation
  (SUMER) on the Solar and Heliospheric Observatory (SOHO). The spectral
  lines formed in the transition region and corona show considerable
  structure and large deviations from a uniform spatial distribution over
  the active region. Enhanced EUV emissions in transition region lines
  are concentrated in small regions outside the umbra of the sunspot
  throughout most of the observing sequence. Only during a short,
  active period do we find an enhanced line emission that reaches into
  the umbra. Preliminary values for the umbral intensity are given.

---------------------------------------------------------
Title: Three Dimensional EUV Imaging of Sunspot Regions Observed
    with SOHO
Authors: Brynildsen, N.; Brekke, P.; Haugan, S. V. H.; Kjeldseth-Moe,
   O.; Maltby, P.; Harrison, R. A.; Rimmele, T.; Wilhelm, K.
1998ASPC..155..171B    Altcode: 1998sasp.conf..171B
  No abstract at ADS

---------------------------------------------------------
Title: The Non-Uniformity in the Sunspot Transition Region
Authors: Brynildsen, N.; Brekke, P.; Fredvik, T.; Haugan, S. V. H.;
   Kjeldseth-Moe, O.; Maltby, P.; Harrison, R. A.; Rimmele, T.;
   Wilhelm, K.
1997ESASP.404..257B    Altcode: 1997cswn.conf..257B
  No abstract at ADS

---------------------------------------------------------
Title: Transition Region Velocities and Line Profiles in the Sunspot
    Region 7981
Authors: Brynildsen, N.; Brekke, P.; Fredvik, T.; Haugan, S. V. H.;
   Kjeldseth-Moe, O.; Maltby, P.; Harrison, R. A.; Pike, C. D.; Rimmele,
   T. Thompson, W. T.; Wilhelm, K.
1997ESASP.404..251B    Altcode: 1997cswn.conf..251B
  No abstract at ADS

---------------------------------------------------------
Title: CDS Observations of the Connection Between Line Intensity
    and Doppler Shift in the Active Region NOAA 7981
Authors: Fredvik, T.; Brynildsen, N.; Maltby, P.; Kjeldseth-Moe, O.;
   Brekke, P.; Haugen, S. V. H.; Harrison, R. A.
1997ESASP.404..391F    Altcode: 1997cswn.conf..391F
  No abstract at ADS

---------------------------------------------------------
Title: The Net Redshifts in EUV Emission Lines and the Connection
    Between Intensity and Doppler Shift
Authors: Brynildsen, N.; Fredvik, T.; Maltby, P.; Kjeldseth-Moe, O.;
   Brekke, P.; Haugan, S. V. H.; Harrison, R. A.; Wilhelm, K.
1997ESASP.404..263B    Altcode: 1997cswn.conf..263B
  No abstract at ADS

---------------------------------------------------------
Title: EUV Line Emission and Time Dependence in the Sunspot Region
    NOAA 7981
Authors: Brynildsen, N.; Brekke, P.; Fredvik, T.; Haugan, S. V. H.;
   Kjeldseth-Moe, O.; Maltby, P.; Harrison, R. A.; Pike, C. D.; Rimmele,
   T.; Thompson, W. T.; Wilhelm, K.
1997ESASP.404..245B    Altcode: 1997cswn.conf..245B
  No abstract at ADS

---------------------------------------------------------
Title: Temporal Variability in the Quiet Sun Transition Region
Authors: Wikstoøl, Ø.; Hansteen, V. H.; Brynildsen, N.; Maltby,
   P.; Kyeldseth-Moe, O.; Harrison, R. A.; Wilhelm, K.; Tarbell, T. D.;
   Scherrer, P. H.
1997ESASP.404..733W    Altcode: 1997cswn.conf..733W
  No abstract at ADS

---------------------------------------------------------
Title: Flows and Dynamics in the Corona Observed with the Coronal
    Diagnostic Spectrometer (cds)
Authors: Brekke, P.; Kjeldseth-Moe, O.; Brynildsen, N.; Maltby, P.;
   Haugan, S. V. H.; Harrison, R. A.; Thompson, W. T.; Pike, C. D.
1997SoPh..170..163B    Altcode:
  EUV spectra obtained with the Coronal Diagnostic Spectrometer (CDS)
  on the Solar and Heliospheric Observatory (SOHO) show significant flows
  of plasma in active region loops, both at coronal and transition region
  temperatures. Wavelength shifts in the coronal lines Mgix 368 Å and
  Mgx 624 Å corresponding to upflows in the plasma reaching velocities
  of 50 km s<SUP>-1</SUP> have been observed in an active region. Smaller
  velocities are detected in the coronal lines Fexvi 360 Å and Sixii
  520 Å. Flows reaching 100 km s<SUP>-1</SUP> are observed in spectral
  lines formed at transition region temperatures, i.e., Ov 629 Å and
  Oiii 599 Å, demonstrating that both the transition region and the
  corona are clearly dynamic in nature. Some high velocity events show
  even higher velocities with line profiles corresponding to a velocity
  dispersion of 300-400 km s<SUP>-1</SUP>. Even in the quiet Sun there
  are velocity fluctuations of 20 km s<SUP>-1</SUP> in transition region
  lines. Velocities of the magnitude presented in this paper have never
  previously been observed in coronal lines except in explosive events
  and flares. Thus, the preliminary results from the CDS spectrometer
  promise to put constraints on existing models of the flows and energy
  balance in the solar atmosphere. The present results are compared to
  previous attempts to observe flows in the corona.

---------------------------------------------------------
Title: Quiet-Sun Connection between the C IV Resonance Lines and
    the Photospheric Magnetic Field
Authors: Brynildsen, Nils; Kjeldseth-Moe, Olav; Maltby, Per
1996ApJ...462..534B    Altcode:
  The quiet-Sun relation between the C iv resonance line parameters and
  the photospheric magnetic field is studied with a spatial resolution of
  1" x 1". The material is ordered into groups according to the magnitude
  of the magnetic flux density, |B|, and conditional probabilities
  are calculated. We find that red shifted profiles with either high
  intensity, large Doppler shift, or large line broadening occupy an
  increasing fraction of the area when |B| increases. These results are
  contrasted by blueshifted profiles which indicate a slight decrease
  with increasing magnetic flux density. The similarity in the results
  obtained with magneto grams taken several hours before and after the
  UV data led us to suggest that the tendency for red shifted profiles
  to outnumber blueshifted profiles in quiet regions originates in the
  super-granular network. <P />Suggestions regarding the origin of the
  redshift phenomenon are briefly confronted with the observations. It
  appears difficult to explain the observations with models based on
  continuous gas flows. However, a model containing Alfvén wave pulses
  traveling from the corona toward the transition region promises to be
  compatible with the observations.

---------------------------------------------------------
Title: High Velocity Event Observed with CDS on SOHO
Authors: Kjeldseth-Moe, O.; Brynildsen, N.; Brekke, P.; Harrison, R. A.
1996AAS...188.3714K    Altcode: 1996BAAS...28..880K
  The Coronal Diagnostic Spectrometer, CDS, on SOHO has observed its
  first strong High Velocity Event. The event occurred on 22 March
  1996 at approximately 13.36 UT and was located in the leg of an
  active region loop. The spectral signature is extremely wide emission
  lines corresponding to a velocity dispersion of approximately 300-450
  km/s. As measured in the 386 A line from Mg IX, the emission also seems
  shifted in wavelength with a redshift corresponding to 65 km/s. The
  intensity contrast in the line is a factor 2 compared to the surrounding
  areas. The spatial extent is small, less than or corresponding to the
  angular resolution of CDS of 4". The event occur in all available lines
  from He I to Fe XV, i.e. over a temperature range from 10 000 K to
  2.2 MK. This is a new result which has not been reported before. The
  relation of this type of event to the well studied explosive events
  is discussed.

---------------------------------------------------------
Title: Transition Region Lines and the Photospheric Magnetic Field
Authors: Maltby, P.; Brynildsen, N.; Kjeldseth-Moe, O.
1996AAS...188.0204M    Altcode: 1996BAAS...28..820M
  We have combined quiet Sun observations of the C riptsize IV resonance
  lines, obtained by the High Resolution Telescope and Spectrograph --
  HRTS during the Spacelab 2 mission with Kitt Peak magnetograms. The
  material is ordered into groups according to the magnitude of
  the magnetic flux density, |B|, and conditional probabilities are
  calculated. We find that redshifted profiles with either high intensity,
  large Doppler shift, or large line broadening occupy an increasing
  fraction of the area when |B| increases. Blueshifted profiles, on the
  other hand, indicate a slight decrease with increasing magnetic flux
  density. The similarity in the results obtained with magnetograms taken
  several hours before and after the UV data led us to suggest that the
  tendency for redshifted profiles to outnumber blueshifted profiles in
  quiet regions originates in the supergranular network.

---------------------------------------------------------
Title: Connection between the C IV resonance lines and the quiet
    sun photospheric magnetic field
Authors: Brynildsen, N.; Kjeldseth-Moe, O.; Maltby, P.
1996ASPC..109..115B    Altcode: 1996csss....9..115B
  No abstract at ADS

---------------------------------------------------------
Title: Quiet-Sun Connection between Intensity, Doppler Shift, and
    Line Broadening in Solar Ultraviolet Emission Lines
Authors: Brynildsen, N.; Kjeldseth-Moe, O.; Maltby, P.
1995ApJ...455L..81B    Altcode:
  The quiet-Sun relations between the C IV line parameters, intensity,
  wavelength shift, and line broadening, are studied with high spatial
  and spectral resolution. The material is ordered into equal intervals
  for one of the line parameters, and conditional probabilities
  are calculated. As the Doppler velocity increases, we find that
  redshifted profiles with a large intensity or line width constitute
  an increasing fraction of the total number of profiles in a given
  velocity interval. For blueshifted profiles, on the other hand, the
  conditional probabilities for finding a profile with considerable
  intensity or line width decrease as the line shift increases. Similar
  relations are found when the material is ordered according to intensity
  or line-width values.

---------------------------------------------------------
Title: On the relation between red- and blueshifted UV-emission
    lines and photospheric magnetic fields
Authors: Brynildsen, N.; Kjeldseth-Moe, Olav; Maltby, Per
1994ESASP.373..413B    Altcode: 1994soho....3..413B
  No abstract at ADS

---------------------------------------------------------
Title: CDS quicklook display software
Authors: Brekke, P.; Haugan, S. V. H.; Brynildsen, Nils
1994ESASP.373..437B    Altcode: 1994soho....3..437B
  No abstract at ADS

---------------------------------------------------------
Title: Fine structure and the emission filling factor
Authors: Kjeldseth-Moe, O.; Brynildsen, N.; Brekke, P.; Maltby, P.
1994SSRv...70...89K    Altcode:
  There is observational evidence for an extreme fine structure in
  the solar transition region, much smaller than 1″ in size (Dereet
  al., 1987, 1988) Corresponding to this extreme fine structure there
  appear to be an equally complex dynamical structure. We review the
  evidence for such dynamical extreme fine structure as demonstrated
  by the frequent appearance of multiple velocities, i.e. distinctly
  different velocities in the transition region occurring within the
  angular resolution element. Multiple velocities are prominent in active
  regions and particularly near sunspots, where velocity components
  may be supersonic. However, multiple velocities are frequent also in
  quiet regions. The consequences of such fine structure for modeling
  the transition region will be outlined. Finally the appropriate CDS and
  SUMER observations needed to extend our knowledge of a finely structured
  transition region and corona, spatially or in time, are discussed.

---------------------------------------------------------
Title: Multiple Flows and the Fine Structure of the Transition Region
    around Sunspots
Authors: Kjeldseth-Moe, O.; Brynildsen, N.; Brekke, P.; Maltby, P.;
   Brueckner, G. E.
1993SoPh..145..257K    Altcode:
  The fine structure in the flow field in the transition region above
  and surrounding a sunspot is determined fromCIV 1548 å line profiles,
  observed with the High Resolution Telescope and Spectrograph (HRTS)
  during the Spacelab 2 mission. The observed line profiles show one, two,
  or three distinct velocity components within the resolution element of
  1″ × 1″. Supersonic flows occur in small regions where the line
  profile has two or three components. The line component that shows
  supersonic speed often is weaker than the subsonic line component,
  which may explain why some observers have been unable to detect the
  supersonic flow component. The broadening of individual line components
  shows non-thermal velocities close to 20 km s<SUP>−1</SUP>. This
  suggests that turbulence is less important than usually considered.

---------------------------------------------------------
Title: Multiple flows in the solar transition region.
Authors: Brekke, P.; Brynildsen, N.; Kjeldseth-Moe, O.; Maltby, P.;
   Brueckner, G. E.
1992ESASP.346..211B    Altcode: 1992ssts.rept..211B
  The solar transition region between the chromosphere and the corona
  shows clear evidence of a fine scale structure that is much smaller
  than the best available instrumental resolution in the UV of 1×1
  arcsec. Previous studies have suggested filling factors of 0.01
  - 0.001, with the solar gas being restricted to thin, extended
  fibrills. New evidence of the fine scale structure is found from
  its dynamical characteristics, the presence of multiple flows. In
  multiple flows the solar gas in small volumes show several distinct
  velocities, resulting in line profiles with more than one velocity
  component within the spatial resolution element. Multiple velocities
  are particularly prominent above sunspots, but by no means restricted
  to these regions. Instead they are clearly a general feature in the
  solar transition region, occurring in quiet as well as active regions.

---------------------------------------------------------
Title: Evidence for fine structure in the solar transition region.
Authors: Brynildsen, N.
1992mrpa.work..141B    Altcode:
  The term fine structure in this paper means sub-resolution
  structures. The arguments for a sub-resolution fine structure in
  the solar transition region come from the following considerations:
  1. Is it possible for the low transition region to radiate away
  the energy conducted into it? 2. The observed vertical extent of
  emission features at the solar limb is much larger than predicted from
  models. 3. Transition region spectral lines show multiple velocities
  along the line-of-sight within the spatial resolution element.

---------------------------------------------------------
Title: Dynamics in the solar transition region.
Authors: Brekke, P.; Brynildsen, N.
1991cwlt.conf...71B    Altcode:
  The authors present an analysis of the dynamical evidence for extreme
  fine structure in the transition region using the Si IV line at
  1402 Å. Gas velocities, line widths and intensities are measured
  from the line profiles by fitting the profiles to a set of Gaussian
  components using a least squares method. Both quiet and active regions
  are studied. The relation of the observed supersonic flow velocities
  to possible shocks in the flow is briefly discussed.

---------------------------------------------------------
Title: Multiple flow velocities in the transition region
Authors: Brekke, P.; Brynildsen, N.; Kjeldseth-Moe, O.; Maltby, P.;
   Bartoe, J. -D. F.; Brueckner, G. E.
1991AdSpR..11e.251B    Altcode: 1991AdSpR..11..251B
  Observations with the High Resolution Telescope and Spectrograph (HRTS)
  of the C IV lines at 1550 Å above sunspots reveal the co-existence
  of several distinct high velocity gas components within the instrument
  resolution element of 1 × 1 arc second. A further investigation of the
  HRTS material demonstrates that such multiple gas velocities are not
  restricted to the temperature region around 10<SUP>5</SUP> K, where the
  C IV lines are formed, but that the gas flows with essentially unchanged
  speed through all temperature layers from 2.5 × 10<SUP>5</SUP> K
  to 10<SUP>4</SUP> K. Furthermore the phenomenon is not restricted to
  sunspots, but occurs also in other solar regions, often most easily
  distinguished in active regions. We describe the characteristics of the
  velocity fields, analyze the mass fluxes and discuss the requirements
  they place on the resolving power of future space instruments.

---------------------------------------------------------
Title: Mass Transport above Sunspots
Authors: Brynildsen, N.; Kjeldseth-Moe, O.; Brueckner, G. E.
1990Ap&SS.170..149B    Altcode:
  Mass transport in the transition zone above a sunspot has been
  studied in the Civ line at 1548 Å, formed at 100 000 K. Four spectral
  rasters have been used, each covering 60×50 are sec. These have been
  observed with the High Resolution Telescope and Spectrograph during
  the Spacelab-2 mission in 1985. Flow velocities are derived from
  multiple Gaussian components fitted to the observed line intensity
  profiles. Density sensitive lines were used to find a relation between
  the Civ line intensity and the particle density. This relation is used
  in the mass flux calculations. The investigation indicates a clear
  net downward mass flux above sunspots.

---------------------------------------------------------
Title: Observed Line Profiles and Mass Fluxes in the Transition
    Region above Sunspots
Authors: Maltby, P.; Brekke, P.; Brynildsen, N.; Kjeldseth-Moe, O.;
   Bartoe, J. -D. F.; Brueckner, G. E.
1990PDHO....7..244M    Altcode: 1990dysu.conf..244M; 1990ESPM....6..244M
  Spectrograms obtained with the HRTS show strong mass flows through
  the transition zone that are particularly prominent above sunspot
  regions. Most characteristic for the flow associated with sunspots
  are regions with supersonic downflows, but upward flowing gas is
  also observed with generally smaller velocities. The flow pattern
  changes from one day to the next and even within a time span of
  minutes. An apparent lack of balance between up- and downflowing
  massfluxes is found. Generally the net massflux appears to be directed
  downward. Possible reasons for this result are briefly discussed in
  terms of observability and line emission area filling factor.

---------------------------------------------------------
Title: Distribution of Velocities in the Pre-Eruptive Phase of a
    Quiescent Prominence
Authors: Engvold, Oddbjørn; Jensen, Eberhart; Zhang, Yi; Brynildsen,
   Nils
1990LNP...363..263E    Altcode: 1990IAUCo.117..263E; 1990doqp.coll..263E
  High resolution Ca II K line spectra of a large quiescent prominence
  were obtained about one hour before a prominence eruption May 2nd
  1974. The observations were made with the main spectrograph of the
  vacuum tower of Sacramento Peak Observatory. The observed velocities
  in a wide range from -50 to +25 km/s suggest that the very initial
  stages of destabilization of the prominence were in fact recorded. The
  distribution of line intensities and line widths versus line shift
  suggest that one observes 3 threads in the line-of-sight for low
  velocities. For larger shifts one is evidently able to observe
  individual threads.

---------------------------------------------------------
Title: Transition Region Massflows Associated with Sunspots
Authors: Kjeldseth-Moe, O.; Brekke, P.; Brynildsen, N.; Maltby, P.;
   Brueckner, G. E.; Bartoe, J. -D. F.
1989BAAS...21.1178K    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Distribution of velocities in the Pre-Eruptive Phase of a
    Quiscent Prominence
Authors: Engvold, O.; Jensen, E.; Zhang, Yi; Brynildsen, N.
1989HvaOB..13..205E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Bildebehandling av solspektra fra romfergen.
Authors: Brekke, P.; Brynildsen, N.
1989ATi....22...49B    Altcode:
  No abstract at ADS

---------------------------------------------------------
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: Gasflows in the transition region above sunspots.
Authors: Kjeldseth-Moe, O.; Brynildsen, N.; Brekke, P.; Bartoe,
   J. -D. F.; Brueckner, G. E.
1987ESASP.275...27K    Altcode: 1987sspp.symp...27K
  Gas flows in the transition region in and above sunspots were observed
  with the High Resolution Telescope and Spectrograph on two rocket
  flights and during the Spacelab 2 mission. Supersonic downflows of
  mass from the corona appear to be generally occurring in sunspots. The
  downflows are often concentrated in regions with typical diameters of
  4000 km on the Sun, suggesting a flow in a looplike structure. However,
  the total flow pattern often has an elongated sheetlike structure
  of much larger extent. Flow speeds are typically 80 km/sec and show
  small variation with the temperature of the radiating gas. Much higher
  flow-speeds (180 km/sec) also occur. Studies of the areas surrounding
  the sunspot in the Spacelab material reveal the presence of upflows over
  extended regions with flow-speeds of 10 to 30 km/sec. It is not clear
  whether the amount of upward flowing gas is sufficient to compensate
  for the mass flux in the downflows.

---------------------------------------------------------
Title: Transition Zone Flows in Sunspots
Authors: Kjeldseth-Moe, O.; Brynildsen, N.; Engvold, O.; Maltby, P.;
   Bartoe, J. -D. F.; Brueckner, G. E.
1987rfsm.conf..317K    Altcode:
  Downflow in the transition region over sunspots first detected on HRTS
  rocket flights, seems to be a general phenomenon. Although details
  in the flow pattern appear to change over a period of minutes, the
  phenomenon itself persists for days. While the mechanism producing the
  observed redshifts is not understood it seems most likely that they are
  produced by actual downflow of gas in thin filamentary structures. This
  may be inferred from the co-existence within the same spatial resolution
  element of tubes with strong downflows and tubes where the gas is at
  rest. Thus the line profiles result from an unresolved fine structure
  in a similar fashion that Evershed effect in the photosphere produces
  "flag"-like line profiles in visual lines.

---------------------------------------------------------
Title: Temperatures of quiescent prominences measured from hydrogen
    Paschen and Ca II IR lines.
Authors: Engvold, Oddbjorn; Brynildsen, Nils
1986NASCP2442...97E    Altcode: 1986copp.nasa...97E
  During 12 to 17 September 1983 a number of prominences were observed
  with the McMatch solar telescope of National Solar Observatories,
  using the Fourier transform spectrometer with a InSb detector (Brault
  1979). The present study refers to three prominences observed 13
  and 14 September. Prominence A: Large quiescent prominence at S28
  E90 Prominence B. Stable prominence in weakly enhanced magnetic
  region at about NO8 E90 Prominence C: Quiescent prominence at N30
  E90. Spectra were obtained at a total of 15 different locations in
  the three prominences in the wavelength range lambda, lambda 7740 to
  14,000 Angstroms. The observed differences between T<SUB>exc</SUB>
  and T<SUB>kin</SUB> are hardly significant. Researchers conclude that
  the two methods for temperature determination when applied to optically
  thin lines give reasonably consistent results, i.e., the population of
  the excited levels of hydrogen is collisionally controlled. The well
  known increase in T and V towards the edge of equiescent prominences
  (Hirayama 1964) is not corroborated by the present data. One explanation
  for this could be that prominence A is atypical. The optical thickness
  of prominence emission lines tends to increase from center to edges as
  demonstrated by the case of He I lambda 10830 angstroms. If line opacity
  plays a significant role in earlier center to edge determinations of
  T and V, a smaller variation would be expected from measurements in
  optically thin lines, such as in the present case.

---------------------------------------------------------
Title: Variability of spectral lines in full-disk observations of
    the sun.
Authors: Barth, S. B.; Brynildsen, N.; Engvold, O.
1983ITABO..59...27B    Altcode:
  Signals of solar activity have been searched for in full-disk line
  spectra of the sun. In the chromospheric lines Ca II H and K,
  and Hα, one finds that the central flux varies in concert with
  solar activity. Hγ shows no clear dependence on activity. Noticeable
  variations in the Ca II line flux are seen in the course of an hour. The
  photospheric Fe I λ5250 Å line tends to get deeper with increasing
  activity.