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Author name code: tapping
ADS astronomy entries on 2022-09-14
author:Tapping, K.F.
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Title: Solar Quiet (Sq) Waveform Interpolation in the Eigenspace
and Its Applications
Authors: Li, Qingmou; Boteler, David; Tapping, Kenneth
2021AGUFMSH35H..10L Altcode:
Solar Quiet (Sq) waveforms recorded at ground geomagnetic stations
reflect solar-terrestrial interactions and have applications
in understanding solar irradiation and dynamo action in the
ionosphere. Naturally, due to no data being available on active
days, Sq records inherently contain gaps. However, currently
available interpolation methods can only handle, by their designation,
point-oriented or scattered observations. Interpolating the Sq variation
with time including the estimated underlying Sq values in the presence
of activity is difficult. In this approach, we develop an interpolation
method, which extracts and uses the temporal patterns in interpolations
to address these requirements. Using this together with the magnetic
quiet days identified using the aa-index, we have processed the ground
geomagnetic observations recorded in Ottawa, Canada during 1968-2019. We
find that our interpolation method is very successful in extracting
full waveforms of temporal modes in Sq. Also, the residuals between
the observed and interpolated values using our algorithm assessment
procedure are acceptable statistically. The Sq signal is highly
auto-correlated, the first eigenvalue or eigenvector owns 99.999%
of total energy, which assures the success of our algorithm. The
algorithm is also able to separate secular and seasonal components
hidden in Sq. We further find that the residuals have high correlation
with magnetic activity index, such as the ap index, which means that
this method can play an important role in separating the quiet and
disturbed components of geomagnetic activity.
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Title: Radio Astronomy and Radio Sources
Authors: Tapping, Ken; Pett, Hugh
2018obha.book..338P Altcode:
No abstract at ADS
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Title: Solar Activity
Authors: Tapping, Ken
2018obha.book..189T Altcode:
No abstract at ADS
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Title: Changing Relationships Between Sunspot Number, Total Sunspot
Area and F<SUB>10.7</SUB> in Cycles 23 and 24
Authors: Tapping, Ken; Morgan, Carly
2017SoPh..292...73T Altcode:
This article is an update of a study (Tapping and Valdès in Solar
Phys.272, 337, 2011) made in the early part of Cycle 24 using
an intercomparison of various solar activity indices (including
sunspot number and the 10.7 cm solar radio flux), in which it was
concluded that a change in the relationship between photospheric and
chromospheric/coronal activity took place just after the maximum of
Cycle 23 and continued into Cycle 24. Precursors (short-term variations)
were detected in Cycles 21 and 22. Since then the sunspot number index
data have been substantially revised. This study is intended to be an
update of the earlier study and to assess the impact of the revision
of the sunspot number data upon those conclusions. This study compares
original and revised sunspot number, total sunspot area, and 10.7
cm solar radio flux. The conclusion is that the transient changes in
Cycles 21 and 22, and the more substantial change in Cycle 23, remain
evident. Cycle 24 shows indications that the deviation was probably
another short-term one.
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Title: Solar Activity
Authors: Tapping, Ken
2017obha.book..189T Altcode:
No abstract at ADS
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Title: Radio Astronomy and Radio Sources
Authors: Tapping, Ken
2016obha.book..338T Altcode:
No abstract at ADS
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Title: Solar Activity
Authors: Tapping, Ken
2016obha.book..189T Altcode:
No abstract at ADS
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Title: Solar Activity
Authors: Tapping, Ken
2015obha.book..189T Altcode:
No abstract at ADS
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Title: Radio Astronomy and Radio Sources
Authors: Tapping, Ken
2015obha.book..338T Altcode:
No abstract at ADS
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Title: Radio Astronomy and Radio Sources
Authors: Tapping, Ken
2014obha.book..338T Altcode:
No abstract at ADS
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Title: Solar Activity
Authors: Tapping, Ken
2014obha.book..189T Altcode:
No abstract at ADS
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Title: The Next Generation of Canadian Solar Flux Monitoring
Authors: Tapping, Kenneth F.; Morton, Donald C.
2013JPhCS.440a2039T Altcode:
The 10.7 cm solar radio flux (F10.7), provided by the National Research
Council of Canada since 1947, is widely used as an index of solar
activity and as a proxy for other solar quantities that are harder to
measure. Over recent years needs have arisen that are difficult to meet
with solar flux measurements at a single wavelength. F10.7 comprises
contributions from multiple emission mechanisms. To separate these,
multi-wavelength measurements are needed. A new instrument is under
construction that will measure fluxes precisely in six bands at 2.8,
3.6, 6.0, 10.7, 18 and 21 cm.
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Title: Radio Sources
Authors: Tapping, Ken
2013obha.book..338T Altcode:
No abstract at ADS
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Title: Solar Activity
Authors: Tapping, Ken
2013obha.book..189T Altcode:
No abstract at ADS
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Title: Radio Sources
Authors: Tapping, Ken
2012obha.book..338T Altcode:
No abstract at ADS
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Title: Solar Activity
Authors: Tapping, Ken
2012obha.book..193T Altcode:
No abstract at ADS
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Title: The Solar Cycle 23 - 24 Minimum. A Benchmark in Solar
Variability and Effects in the Heliosphere
Authors: White, O.; Kopp, G.; Snow, M.; Tapping, K.
2011SoPh..274..159W Altcode:
Given the numerous ground-based and space-based experiments producing
the database for the Cycle 23 - 24 Minimum epoch from September 2008
to May 2009, we have an extraordinary opportunity to understand its
effects throughout the heliosphere. We use solar radiative output
in this period to obtain minimum values for three measures of the
Sun's radiative output: the total solar irradiance, the Mg II index,
and the 10.7 cm solar radio flux. The derived values are included in
the research summaries as a means to exchange ideas and data for this
long minimum in solar activity.
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Title: Did the Sun Change Its Behaviour During the Decline of Cycle
23 and Into Cycle 24?
Authors: Tapping, K. F.; Valdés, J. J.
2011SoPh..272..337T Altcode:
The activity minimum between the end of cycle 23 and the beginning
of cycle 24 was the longest and deepest since at least the beginning
of the 20th century. This has led to speculation that the Sun is
changing its behaviour. The sunspot number and 10.7-cm solar radio flux
indices have traditionally been highly correlated, so a change in the
relationship between them might flag at such a change. An examination
of this relationship suggests a significant change in the relationship
between activity in the photosphere and in the chromosphere/corona
happened soon after the maximum of cycle 23 and has continued into
cycle 24. However, there are indications of change as early as 1980.
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Title: Solar Activity
Authors: Tapping, Ken
2011obha.book..192T Altcode:
No abstract at ADS
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Title: Radio Sources
Authors: Tapping, Ken
2011obha.book..341T Altcode:
No abstract at ADS
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Title: Solar Activity
Authors: Tapping, Ken
2010obha.book..187T Altcode:
No abstract at ADS
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Title: Radio Sources
Authors: Tapping, Ken
2010obha.book..329T Altcode:
No abstract at ADS
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Title: Solar Activity
Authors: Tapping, Ken
2009obha.book..193T Altcode:
No abstract at ADS
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Title: Radio Sources
Authors: Tapping, Ken
2009obha.book..335T Altcode:
No abstract at ADS
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Title: Solar Activity
Authors: Tapping, Ken
2008obha.book..180T Altcode:
No abstract at ADS
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Title: Radio protection zone evaluation at the Dominion Radio
Astrophysical Observatory
Authors: Tapping, Ken
2008cosp...37.3150T Altcode: 2008cosp.meet.3150T
Increasing use of the radio spectrum by licensed and unlicensed
devices, together with the encroachment of housing developments are an
issue facing many radio observatories, including the Dominion Radio
Astrophysical Observatory (DRAO), located near Penticton in Southern
British Columbia. A joint study by Industry Canada (Canada's national
spectrum manager), and the National Research Council (Operator of
DRAO) is currently in progress to examine protection zone needs and
the reliability of the definitions of the zone, and the general level
of background noise from growing local communities. The objectives
are to produce a definition of a protection zone that is useful in
spectrum management to protect the observatory, and to establish how
much local community development is acceptable if the observatory is
to remain a viable location for radio astronomical observations. This
presentation will summarize the results so far in this ongoing study.
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Title: Radio Sources
Authors: Tapping, Ken
2008obha.book..308T Altcode:
No abstract at ADS
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Title: Solar Magnetic Activity and Total Irradiance Since the
Maunder Minimum
Authors: Tapping, K. F.; Boteler, D.; Charbonneau, P.; Crouch, A.;
Manson, A.; Paquette, H.
2007SoPh..246..309T Altcode:
We develop a model for estimating solar total irradiance since 1600
AD using the sunspot number record as input, since this is the only
intrinsic record of solar activity extending back far enough in
time. Sunspot number is strongly correlated, albeit nonlinearly with
the 10.7-cm radio flux (F<SUB>10.7</SUB>), which forms a continuous
record back to 1947. This enables the nonlinear relationship to be
estimated with usable accuracy and shows that relationship to be
consistent over multiple solar activity cycles. From the sunspot
number record we estimate F<SUB>10.7</SUB> values back to 1600
AD. F<SUB>10.7</SUB> is linearly correlated with the total amount of
magnetic flux in active regions, and we use it as input to a simple
cascade model for the other magnetic flux components. The irradiance
record is estimated by using these magnetic flux components plus
a very rudimentary model for the modulation of energy flow to the
photosphere by the subphotospheric magnetic flux reservoir feeding the
photospheric magnetic structures. Including a Monte Carlo analysis of
the consequences of measurement and fitting errors, the model indicates
the mean irradiance during the Maunder Minimum was about 1 ± 0.4 W
m<SUP>−2</SUP> lower than the mean irradiance over the last solar
activity cycle.
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Title: Radio Sources
Authors: Tapping, Ken
2007obha.book..273T Altcode:
No abstract at ADS
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Title: Solar Activity
Authors: Tapping, Ken
2007obha.book..159T Altcode:
No abstract at ADS
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Title: Radio Sources
Authors: Tapping, Ken
2006obha.book..289T Altcode:
No abstract at ADS
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Title: Solar Activity
Authors: Tapping, Ken
2006obha.book..175T Altcode:
No abstract at ADS
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Title: Sunspot fragmentation and total solar irradiance modelling
Authors: Crouch, A. D.; Charbonneau, P.; Tapping, K. F.; Paquin-Ricard,
D.
2005AGUSMSH23B..03C Altcode:
Observational evidence suggests that sunspot decay is due, at least
in part, to a fragmentation process. We have developed a model for
this, where the sunspot fragmentation produces an ensemble of small
scale magnetic flux tubes, which themselves can remain at the surface
for many days. The number of sunspots emerging at the solar surface
varies over the 11 year solar activity cycle. Consequently, the size
distribution of magnetic structures is also modulated by the cycle. The
simplicity of our model allows us to track the evolution of this
distribution over very long time scales (many solar cycles). There are
several applications for such a model. For example, to the total solar
irradiance, which also varies over the solar cycle. Broadly speaking,
the irradiance contribution from different magnetic features depends
on their size (large features, such as sunspots, are dark, whereas
small flux tubes tend to be bright). By combining this property with
our sunspot fragmentation model, we show that the resultant system
can produce an irradiance contribution that behaves very much like the
observed total solar irradiance. Our model has several input parameters
(one crucial example is the actual relationship between the size of a
magnetic feature and its brightness). We have used a genetic algorithm
to adjust the parameters in order to optimize the agreement between
our model and the observations. Will we discuss those results and
also comment on the contribution our model makes to the weak field
component of solar magnetic flux budget.
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Title: Solar Activity
Authors: Tapping, Ken
2005obha.book..106T Altcode:
No abstract at ADS
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Title: Radio Sources
Authors: Tapping, Ken
2005obha.book..289T Altcode:
No abstract at ADS
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Title: Radio Sources
Authors: Tapping, Ken
2004obha.book..289T Altcode:
No abstract at ADS
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Title: Solar Activity
Authors: Tapping, Ken
2004obha.book..104T Altcode:
No abstract at ADS
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Title: Tracing space weather disturbances from the Sun through to
their effects on the ground
Authors: Boteler, D. H.; Tapping, K. F.
2004cosp...35.4052B Altcode: 2004cosp.meet.4052B
Recordings from the RTSN and Penticton radio telescopes are used to
investigate the solar eruptions that gave rise to major magnetic
disturbances and power system problems on the Earth. Radio flux
measurements provide valuable information on the timing and speed of
eruptions rising from the Sun's surface. Using the delays in increased
flux at different frequencies we determine the speed of eruptions up
through different heights in the solar atmosphere. These speeds provide
a guide to when each eruption should arrive at the earth which can
be correlated with times of geomagnetic disturbances. Times of shock
arrivals and the subsequent evolution of the geomagnetic disturbance
are examined to identify the specific causes of power system problems
on the ground.
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Title: Book Review: The enigma of sunspots / Floris Books, 2002
Authors: Tapping, Ken
2003Obs...123..233T Altcode:
No abstract at ADS
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Title: S-Component Sources at 21 cm Wavelength in the Rising Phase
of Cycle 23
Authors: Tapping, K. F.; Cameron, H. T.; Willis, A. G.
2003SoPh..215..357T Altcode:
The Synthesis Radio Telescope at the Dominion Radio Astrophysical
Observatory is being used to make a long-term study of the relationship
between sources of the slowly-varying component at 21-cm wavelength
and the active regions with which they are associated. Although the
arc-minute angular resolution of the radio telescope is insufficient
to map individual active regions, the unique capability of this radio
telescope to map the whole solar disc in a single operation makes
it useful for identifying and measuring sources of the slowly-varying
component, which at this wavelength are largely due to free-free thermal
emission from plasma concentrations trapped in active region magnetic
fields. The brightness temperatures of the emission are higher in
large, complex active regions, suggesting the plasma slab producing
the emission is thicker and/or denser in such regions. We find also
that the relationship between the brightness temperature and the size
and complexity of the host region is a function of the phase of the
10-13-year solar activity cycle.
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Title: Sources of the Slowly-Varying Component of Solar Microwave
Emission and their Relationship with their Host Active Regions
Authors: Tapping, K. F.; Zwaan, C.
2001SoPh..199..317T Altcode:
Daily surveys of the solar disc made at 2.8 cm wavelength over
the period 1-13 November 1981, complemented by magnetograms and
Hα filtergrams, are used to examine the relationship between
sources of the slowly varying component of solar radio emission and
properties of their host regions. Two classes of source are noted:
diffuse and compact. Sources are designated compact when smaller than
40”. The diffuse sources may be explained in terms of free - free
thermal emission from trapped plasma in loops overlying the active
region. The great majority of compact sources can be accounted for in
terms of gyroresonance from thermal electrons in the strong magnetic
fields overlying sunspots. A small minority are less amenable to
this explanation. They are associated with magnetic complexity and
dynamism, lie close to magnetic polarity reversals, and could be
non-thermal. Microwave sources are an evolutionary feature common to
all but the smallest active regions.
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Title: Solar Activity Indices
Authors: Tapping, K.
2000eaa..bookE2047T Altcode:
Solar activity is driven by the temporally and spatially varying
distribution of magnetic flux in the photosphere, chromosphere and
corona. It covers a range of phenomena at all levels in the solar
atmosphere and time-scales ranging from seconds and minutes (SOLAR
FLARES and SOLAR CORONAL MASS EJECTIONS), through months (the evolution
of ACTIVE REGIONS and SOLAR ACTIVITY COMPLEXES), to the 11 (or...
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Title: The Low-Resolution DRAO Survey of H I Emission from the
Galactic Plane
Authors: Higgs, L. A.; Tapping, K. F.
2000AJ....120.2471H Altcode:
A survey of H I line emission in the Galactic plane from Galactic
longitude l=72.2d to 149° 0, and latitude b=-5.4d to 7.2d, has been
made using the 26-m Telescope at the Dominion Radio Astrophysical
Observatory. Spectra were observed at 0.2d intervals of longitude
and latitude, providing a survey which is fully sampled in the spatial
domain. A detailed study of the antenna characteristics of the telescope
allowed the correction of the spectra for stray radiation. The spectral
resolution is 1.32 km s<SUP>-1</SUP>, and the LSR velocity range is
-260 to 161 km s<SUP>-1</SUP>. The final spectra have an estimated
T<SUB>b</SUB> scaling accuracy of 1% and an estimated rms noise in one
channel (0.8245 km s<SUP>-1</SUP>) of 0.25 K. A region of suspected
strong H I self-absorption at l~92<SUP>deg</SUP>, b~3<SUP>deg</SUP>,
has been identified. Comparison with spectra from the Leiden/Dwingeloo
Survey is used to estimate the overall accuracy of the stray radiation
corrections. This comparison also shows that a small percentage (~1%)
of the spectra in the latter survey suffer from calibration errors
exceeding 10%. A table of positions of the more discordant spectra
is given.
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Title: The Canadian Galactic Plane Survey - Phase 2.
Authors: Landecker, T. L.; Knee, L. B. G.; Brunt, C.; Dewdney, P. E.;
Dougherty, S. M.; Galt, J. A.; Gray, A. D.; Higgs, L. A.; Kothes, R.;
Purton, C. R.; Roger, R. S.; Tapping, K.; Wallace, B. J.; Willis,
A. G.; Brown, J. C.; Gibson, S. J.; Leahy, D. A.; Peracaula, M.;
Taylor, A. R.; Wilder, S.; Foster, T.; Routledge, D.; Vaneldik, J. F.;
McCutcheon, W. H.; Basu, S.; Johnstone, D. I.; Kerton, C.; Martin,
P. G.; Cazzolato, F.; Gagnon, E.; Germain, S.; Ghazzali, N.; Godbout,
S.; Joncas, G.; Maschenko, S. Y.; Miville-Deschènes, M. -A.; Pineault,
S.; Carignan, C.; St-Louis, N.; Christie, R. A.; Irwin, J. A.; Brar,
R.; Fich, M.; Zhang, X. -Z.; Heiles, C. E.; Normandeau, M.; Terebey,
S.; Heyer, M. H.; Wendker, H. J.; Beichman, C. A.; Moriarty-Schieven,
G. H.; Green, D. A.; Duric, N.; English, J.
1999JRASC..93..182L Altcode:
No abstract at ADS
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Title: Studies of changing patterns of solar activity using the DRAO
Synthesis Radio Telescope.
Authors: Tapping, K.; Burke, I.; Cameron, H.; Harvey, K.; Zwaan, C.
1999JRASC..93Q.186T Altcode:
No abstract at ADS
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Title: Obituary notice: John R. Smith, 1924-1998
Authors: Tapping, K.
1999JBAA..109...98T Altcode:
No abstract at ADS
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Title: The Sun's energy output and the 10.7 cm flux.
Authors: Tapping, K. F.
1998JRASC..92Q.319T Altcode:
No abstract at ADS
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Title: The Canadian Galactic plane survey.
Authors: Taylor, A. R.; Gibson, S.; Leahy, D.; Peracaula, M.;
Dougherty, S.; Carignan, C.; St-Louis, N.; Fich, M.; Ghazzali, N.;
Joncas, G.; Pineault, S.; Mashchenko, S.; Irwin, J.; English, J.;
Heiles, C.; Normandeau, M.; Martin, P.; Johnstone, D.; Basu, S.;
McCutcheon, W.; Routledge, D.; Vaneldik, F.; Dewdney, P.; Galt, J.;
Gray, A.; Higgs, L.; Knee, L.; Landecker, T.; Purton, C.; Roger,
R. S.; Tapping, K.; Wallace, B.; Willis, T.; Beichman, C.; Duric,
N.; Green, D.; Heyer, M.; Wendker, H.; Zhang, Xizhen
1998JRASC..92R.319T Altcode:
No abstract at ADS
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Title: The Canadian Galactic Plane Survey
Authors: English, J.; Taylor, A. R.; Irwin, J. A.; Dougherty, S. M.;
Basu, S.; Beichman, C.; Brown, J.; Cao, Y.; Carignan, C.; Crabtree,
D.; Dewdney, P.; Duric, N.; Fich, M.; Gagnon, E.; Galt, J.; Germain,
S.; Ghazzali, N.; Gibson, S. J.; Godbout, S.; Gray, A.; A. Green, D.;
Heiles, C.; Heyer, M.; Higgs, L.; Jean, S.; Johnstone, D.; Joncas,
G.; Landecker, T.; Langer, W.; Leahy, D.; Martin, P.; Matthews, H.;
McCutcheon, W.; Moriarity-Scheiven, G.; Pineault, S.; Purton, C.;
Roger, R.; Routledge, D.; St-Louis, N.; Tapping, K.; Terebey, S.;
Vaneldik, F.; Watson, D.; Wendker, H.; Willis, T.; Zhang, X.
1998PASA...15...56E Altcode:
The Dominion Radio Astrophysical Observatory (DRAO) is carrying out a
survey as part of an international collaboration to image the northe,
at a common resolution, in emission from all major constituents of
the interstellar medium; the neutral atomic gas, the molecular gas,
the ionised gas, dust and relativistic plasma. For many of these
constituents the angular resolution of the images (1 arcmin) will
be more than a factor of 10 better than any previous studies. The
aim is to produce a publicly-available database of high resolution,
high-dynamic range images of the Galaxy for multi-phase studies of
the physical states and processes in the interstellar medium. We
will sketch the main scientific motivations as well as describe some
preliminary results from the Canadian Galactic Plane Survey/Releve
Canadien du Plan Galactique (CGPS/RCPG).
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Title: The low-resolution DRAO survey of H I emission from the
Galactic plane.
Authors: Higgs, L. A.; Davies, M.; Galt, J. A.; Hovey, G. J.; Knee,
L. B. G.; Tapping, K. F.; Willis, A. G.
1998JRASC..92R..29H Altcode:
No abstract at ADS
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Title: The Canadian Galactic Plane Survey.
Authors: Gibson, S.; Taylor, A. R.; Leahy, A.; Dougherty, S.;
Carignan, C.; St. -Louis, N.; Fich, M.; Ghazzali, N.; Joncas, G.;
Pineault, S.; Normandeau, M.; Heiles, C.; Irwin, J.; English, J.;
Martin, P.; Johnstone, D.; Basu, S.; McCutcheon, W.; Routledge, D.;
Vaneldik, F.; Dewdney, P.; Galt, J.; Gray, A.; Higgs, L.; Knee, L.;
Landecker, T.; Purton, C.; Roger, R. S.; Tapping, K.; Willis, T.;
Moriarty-Schieven, G.; Beichman, C.; Terebey, S.; Duric, N.; Green,
D.; Heyer, M.; Wendker, H.; Zhang, Xizhen
1998JRASC..92...28G Altcode:
No abstract at ADS
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Title: The Low-Resolution DRAO Survey of H 1 Emission from the
Galactic Plane
Authors: Higgs, L. A.; Tapping, K. F.
1997AAS...191.5004H Altcode: 1997BAAS...29R1294H
The survey of H 1 emission from the Galactic plane which is currently
underway using the Synthesis Telescope at the Dominion Radio
Astrophysical Observatory (DRAO), as a major part of the Canadian
Galactic Plane Survey, requires single-dish observations of H 1
emission to provide structural information that is missing from the
interferometric observations (the so-called “short spacing” data). A
fast H 1 line survey of about 1000 square degrees of the Galactic
plane, which will be used for this purpose, is now being carried out
using the DRAO 26-m Telescope. This survey of H 1 line emission will
be fully sampled spatially, yielding nearly 25,000 spectra covering
the velocity range of -260 km/s to 160 km/s. The survey covers the
Galactic longitude range of 72.2arcdeg to 149arcdeg , between Galactic
latitudes of -5.4arcdeg and 7.2arcdeg . The spectra have 512 channels
with a resolution of 1.3 km/s. The survey will be completed in 1997
and the data will then be corrected for the effects of sidelobe
contamination. Initial results of the survey will be presented.
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Title: The DRAO Galactic Plane Survey Project
Authors: Dougherty, S. M.; Dewdney, P.; Galt, J.; Gray, A.; Higgs, L.;
Landecker, T.; Purton, C.; Roger, R.; Tapping, K.; Willis, T.; Taylor,
A. R.; Leahy, D.; Carignan, C.; St-Louis, N.; Fich, M.; Ghazzali,
N.; Irwin, J.; Joncas, G.; Pineault, S.; Martin, P.; McCutcheon, W.;
Routledge, D.; Vaneldik, F.; Matthews, H.; Moriarity-Scheiven, G.;
Beichman, C.; Terebey, S.; Duric, N.; Green, D.; Heiles, C.; Heyer,
M.; Langer, W.; Watson, D.; Wendker, H.; Zhang, X.
1996AAS...189.1704D Altcode: 1996BAAS...28.1295D
The Dominion Radio Astrophysical Observatory, in collaboration with a
consortium of university astronomers, has begun a survey of the atomic
hydrogen and radio continuum emission from our Milky Way galaxy. By
constructing a mosaic of 186 synthesis fields, the survey will cover the
region 75(deg) < l < 145(deg) and -3(deg) < b < +5(deg) ,
with angular resolution of ~ 1'. Within this region the observations
will yield an atomic hydrogen cube with 256 channels with velocity
resolution of 1.2 km s(-1) , Stokes I, Q, U and V continuum images at
1420 MHz and a Stokes I continuum image at 408 MHz. The DRAO survey
is part of an international collaboration to image the Milky Way,
at a common resolution, in emission from all major constituents of
the interstellar medium; the neutral atomic gas, the molecular gas,
the ionized gas, dust and relativistic plasma. For many of these
constituents the angular resolution of the images will be more than a
factor of 10 better than any previous studies. The aim is to produce a
database of high resolution, high-dynamic range images of the Galaxy
for multi-phase studies of the physical states and processes in the
interstellar medium. We present some preliminary images from the survey
project as well as highlights of some initial scientific results.
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Title: Flares and energy dissipation in solar active regions.
Authors: Tapping, K.
1996JRASC..90..322T Altcode:
No abstract at ADS
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Title: The DRAO galactic plane survey project.
Authors: Taylor, A. R.; Leahy, D.; Carignan, C.; St-Louis, N.; Fich,
M.; Ghazzali, N.; Irwin, J.; Joncas, G.; Pineault, S.; Martin, P.;
McCutcheon, W.; Routledge, D.; Vaneldik, F.; Dewdney, P.; Dougherty,
S.; Galt, J.; Gray, A.; Higgs, L.; Landecker, T.; Purton, C.; Roger,
R.; Tapping, K.; Willis, T.; Matthews, H.; Moriarty-Schieven, G.;
Crabtree, D.; Beichman, C.; Terebey, S.; Duric, N.; Green, D.; Heiles,
C.; Heyer, M.; Langer, W.; Watson, D.; Wendker, H.; Zhang, X.
1996JRASC..90..326T Altcode:
No abstract at ADS
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Title: Schoolyard and backyard experiments in astronomy.
Authors: Tapping, K. F.
1995JRASC..89R.160T Altcode:
No abstract at ADS
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Title: Solar active regions and sources of the S-component.
Authors: Tapping, K. F.
1995JRASC..89..169T Altcode:
No abstract at ADS
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Title: Imaging the Sun at 21 cm: Budgetting the S-Component
Authors: Burke, I. E.; Tapping, K. F.
1995SoPh..157..295B Altcode:
On fourteen days in July and August 1992 and June 1993, we used the
7-element synthesis radio telescope at the Dominion Radio Astrophysical
Observatory to make full-disc, arc-min resolution images of the Sun
at 21 cm, with the objective of budgetting the contributions to the
slowly-varying component of solar radio emission. This instrument
has the advantage that the mapping field at this wavelength is about
2.5° wide. However, it has also the severe disadvantage that with
only 12 hours to record each image, the brightness distribution is
severely undersampled. This difficulty, along with solar rotation and
declination motion during each observation, required development of
special image correction procedures.
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Title: Discrete microwave sources in solar active regions
Authors: Tapping, Kenneth Frank
1995PhDT.......112T Altcode:
No abstract at ADS
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Title: Solar microwave emission and coronal structure.
Authors: Tapping, K. F.
1994JRASC..88..253T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Limits to the Accuracy of the 10.7-CENTIMETER Flux
Authors: Tapping, K. F.; Charrois, D. P.
1994SoPh..150..305T Altcode:
The 10.7 cm flux data, which are widely used as an index of solar
activity, are actually spot measurements of the solar flux density
at 10.7 cm wavelength, made three times each day, usually at 17:00,
20:00, and 23:00 UT. These values, or the 20:00 UT determination alone,
are frequently used as the average flux for that day. Since each spot
measurement takes about one hour to make, and the Sun's emissions at
that wavelength can vary over time scales shorter than the intervals
between the measurements, the data are unavoidably undersampled. Radio
emissions from transient events, such as flares, are defined as
contaminants of the flux, and largely-empirical procedures have evolved
which are used to filter them from the data.
---------------------------------------------------------
Title: A Nearby Star
Authors: Tapping, K.
1994JRASC..88....1T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Slowly-Varying Microwave Emissions from the Solar Corona
Authors: Tapping, K. F.; Harvey, K. L.
1994svsp.coll..181T Altcode: 1994IAUCo.143P.181T
No abstract at ADS
---------------------------------------------------------
Title: Change in the radiative output of the Sun in 1992 and its
effect in the thermosphere
Authors: White, O. R.; Rottman, G. J.; Woods, T. N.; Knapp, B. G.;
Keil, S. L.; Livingston, W. C.; Tapping, K. F.; Donnelly, R. F.;
Puga, L. C.
1994JGR....99..369W Altcode:
Ground and space measurements of the solar spectral irradiance at radio,
visible, UV, and X ray wavelengths show a large decline in the first 6
months of 1992. This sustained drop in the solar output is important
in understanding the connection between the emergent magnetic flux
on the Sun and the radiative output as well as in understanding the
effects of such change in the upper atmosphere of the earth. We present
preliminary estimates of the observed changes as the means to spur
inquiry into this solar event in the declining phase of solar cycle
22. Typical decreases are 15% in Lyman alpha and 40% in 10.7-cm radio
flux. Mass spectrometer and incoherent scatter model calculations at
600 km in the thermosphere indicate a 30% decrease in the temperature
and a 3X decrease in the density of the thermosphere near the altitude
where both the Upper Atmosphere Research Satellite (UARS) and Hubble
Space Telescope (HST) are flying. Decrease of the orbital period of
the UARS shows the expected effect of decreasing density at flight
altitude. Work in progress indicates that the output change results
from the decline in solar magnetic flux to a lower level of activity
in the southern hemisphere of the Sun.
---------------------------------------------------------
Title: Mapping the Sun using the DRAO Synthesis Telescope.
Authors: Burke, I.; Tapping, K.
1993JRASC..87Q.177B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A model for non-thermal sources in solar active regions.
Authors: Tapping, K.
1993JRASC..87..209T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The sources of the slowly-varying component.
Authors: Tapping, K. F.; Madden, J. D.; Burke, I. E.
1992JRASC..86..276T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Adaptive potential drops as energy dissipators in solar
magnetic structures.
Authors: Tapping, K. F.
1991JRASC..85..178T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Using the Radio Schmidt Telescope to Study Solar Active Regions
Authors: Tapping, K. F.
1991rst..work..155T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Solar Radio Astronomy Programme at the National Research
Council of Canada
Authors: Tapping, K. F.
1991BAAS...23.1039T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A brief history of the Indian River Observatory radio
interferometer.
Authors: Roy, Frank; Tapping, Ken
1990JRASC..84..260R Altcode:
The construction and evolution of a large amateur-built radiotelescope
over the past 14 years is presented. To illustrate the improvements
in sensitivity achieved during the project, examples of observations
made with the instrument are described.
---------------------------------------------------------
Title: The Origin of the 10.7-CM Flux
Authors: Tapping, K. F.; Detracey, B.
1990SoPh..127..321T Altcode:
We propose that when all sources on the solar disc are taken into
account, the S component at 10.7 cm wavelength is dominated by thermal
free-free (bremsstrahlung) emission. It is not produced only in the
vicinity of sunspots; more than 60% of the total flux may be due
to a widely-distributed emission associated with the hot complexes
of activity. Using a model for the solar atmosphere based upon an
assumption of weak (or vertical) magnetic fields, the spectrum of
the S-component is calculated and its sensitivity to changes in
the model parameters investigated. Variation of the thicknesses of
the chromosphere, transition region and mixed zone cause only small
changes in the S-component spectrum; there is a much stronger dependence
upon the plasma density, particularly at the base of the corona. The
behaviour of the S-component at 10.7 cm wavelength is examined in
more detail. We find that the largest contribution to the 10.7 cm flux
originates in the low corona, that structural changes affect it only
slightly, but that it is strongly density-related. This dependence
upon few quantities, together with its relative localization in the
low corona, contributes to the usefulness of the 10.7 cm flux as an
index of solar activity.
---------------------------------------------------------
Title: Relationships Between Active Region Emissions at 2. 8cm and
Indicators of Dynamic Processes
Authors: Tapping, K. F.
1989BAAS...21..828T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The 10.7-cm microwave observations of AR 5395 and related
terrestrial effects
Authors: Gaizauskas, V.; Hughes, T. J.; Tapping, K. F.
1989dots.work..242G Altcode:
The 10.7 cm flux patrols in Canada recorded 4 Great Bursts (peaks
greater than 500 sfu) during the disk passage of AR 5395 in March
1989. The Great Bursts of 16 and 17 March were simple events of great
amplitude and with half-life durations of only several minutes. Earlier
Great Bursts, originating on 6 March towards the NE limb and on 10 March
closer to the central meridian, belong to an entirely different category
of event. Each started with a very strong impulsive event lasting just
minutes. After an initial recovery, however, the emission climbed back
to level as greater or greater than the initial impulsive burst. The
events of 6 and 10 March stayed above the Great Burst threshold for
at least 100 minutes. The second component of long duration in these
cases is associated with Type 4 continuum emission and thus very likely
with CMEs. Major geomagnetic disturbances did not occur as a result
of the massive complex event of 6 March or the two simple but strong
events of 16 and 17 March. But some 55 hours after the peak in the
long-enduring burst of 10 March, a storm began which qualifies as the
fourth strongest geomagnetic storm in Canada since 1932. The vertical
component of the earth's field measured during the storm by a fluxgate
magnetometer at a station in Manitoba is presented. Within a minute of
the sudden commencement of this storm, a series of breakdowns began in
the transmission system of Hydro-Quebec which resulted in a total loss
of power, on a bitterly cold winter's day, for at least 10 hours. The
loss of power provoked an enormous outcry from the public resulting
in the power utilities being more receptive to the need to monitor
solar as well as geomagnetic activity.
---------------------------------------------------------
Title: The Origins of the 10.7-CM Solar Flux
Authors: Tapping, K. F.; Gaizauskas, V.
1988JRASC..82..280T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Compact Sites of Microwave Emission at 2.8 Centimeter
Wavelength inside Solar Active Regions
Authors: Gaizauskas, V.; Tapping, K. F.
1988ApJ...325..912G Altcode:
The authors have located the positions of 59 hot, compact sources of
2.8 cm emission in 28 active regions with respect to photospheric and
chromospheric structures. The same regions were photographed at high
spatial resolution on the same days through a wavelength-scanning
Hα filter. Almost 90% of these compact sources are associated with
either a plage or a polarity reversal (or both together); they are
found in just part of a plage (or polarity reversal) which may be
one of several in the same active region. The authors propose that
the observed properties of these compact sources can be explained in
terms of emission from current-driven instabilities which are excited
by evolutionary stresses acting on active regions.
---------------------------------------------------------
Title: The Thermal Contribution to the 10.7 cm Flux
Authors: Tapping, K.
1988srov.proc..135T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Search for X-Rays from the Region of the Aries-Perseus Flasher
Authors: Lewin, Walter H. G.; van Paradijs, Jan; Damen, Eugene;
Jansen, Fred; McCall, Marshall L.; Feldman, P. A.; Tapping, K. F.
1987AJ.....94..429L Altcode:
The region containing the Perseus flasher (Katz et al., 1986) was
observed for 5.4 hr with the EXOSAT observatory. Upper limits (2 σ
levels of confidence) to a point source with a steady X-ray flux were
2×10<SUP>-12</SUP>erg cm<SUP>-2</SUP>s<SUP>-1</SUP> (0.1 - 2 keV) and
6×10<SUP>-12</SUP>erg cm<SUP>-2</SUP>s<SUP>-1</SUP> (1 - 20 keV). Upper
limits (4 σ level of confidence) to X-ray flashes of ≡1 s duration
were 4×10<SUP>-9</SUP>erg cm<SUP>-2</SUP>s<SUP>-1</SUP> (0.1 - 2 keV)
and 7×10<SUP>-10</SUP>erg cm<SUP>-2</SUP>s<SUP>-1</SUP> (1 - 20 keV).
---------------------------------------------------------
Title: Compact Sources of Microwave Emission at 2.8 cm Wavelength
Inside Solar Active Regions
Authors: Gaizauskas, V.; Tapping, K. F.
1987BAAS...19..942G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Microwave Emission from Evolving Active Regions
Authors: Tapping, K. F.
1987BAAS...19Q.943T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Recent solar radio astronomy at centimeter wavelengths:
the temporal variability of the 10.7-cm flux.
Authors: Tapping, K. F.
1987JGR....92..829T Altcode:
Studies made by means of high-resolution radio telescopes indicate
that solar centimetric emission contains contributions from many
different sources and involves more than one radiation mechanism. Two
emission components have been identified: bright, compact sources
and weaker, diffuse emission which is distributed over the plage
and surrounding areas of enhanced magnetic field. There is evidence
for the occurrence of weaker but widely distributed radiation from
elements of the active network. The good correlation between the 10.7-cm
flux and shorter-wavelength indicators of solar activity, such as Ca
II emission, suggests that gyromagnetic processes contribute little
to the total centimetric flux. If the 10.7-cm flux is predominantly
thermal (free-free) emission, its intensity will be a measure of the
total amount of magnetic flux emerging through the photosphere and
supporting density enhancements in the lower solar atmosphere.
---------------------------------------------------------
Title: Solar VLBI of Compact Transient Sources
Authors: Tapping, K. F.
1986SoPh..104..199T Altcode:
Very Long Baseline Interferometry offers the only technique for
resolving the transient compact sources which, according to an
increasing weight of observational and theoretical evidence, occur
during solar flares. In this paper we discuss the problems of applying
VLBI to observing the Sun, the results obtained so far and how the
technique may be effectively employed in future studies of compact
emission structures in solar flares.
---------------------------------------------------------
Title: A double layer model for solar X-ray and microwave pulsations.
Authors: Tapping, K. F.
1986NASCP2449..445T Altcode: 1986rfsf.nasa..445T
The wide range of wavelengths over which quasi-periodic pulsations have
been observed suggests that the mechanism causing them acts upon the
supply of high energy electrons driving the emission processes. A model
is described which is based upon the radial shrinkage of a magnetic
flux tube. An instability takes place in the tube throat, resulting
in the formation of a potential double layer, which then accelerates
electrons and ions to MeV energies. The double layer can be unstable,
collapsing and reforming repeatedly. The resulting pulsed particle
beams give rise to pulsating emissions which are observed at radio
and X-ray wavelengths.
---------------------------------------------------------
Title: Solar VLBI.
Authors: Tapping, K. F.; Kuijpers, J.
1986NASCP2449..211T Altcode: 1986rfsf.nasa..211T
In April, 1981, radio telescopes at Dwingeloo (The Netherlands)
and Onsala (Sweden) were used as a long-baseline interferometer at a
wavelength of 18 cm. The baseline of 619 km gave a spatial resolution on
the Sun of about 45 km. The major problems of Solar Very Long Baseline
Interferometry are discussed.
---------------------------------------------------------
Title: Rapid spectral and flux time variations in a solar burst
observed at various dm-mm wavelengths and at hard X-rays.
Authors: Zodivaz, A. M.; Kaufmann, P.; Correia, E.; Costa, J. E. R.;
Takakura, T.; Cliver, E. W.; Tapping, K. F.
1986NASCP2449..171Z Altcode: 1986rfsf.nasa..171Z
A solar burst was observed with high sensitivity and time resolution
at cm-mm wavelengths by two different radio observatories; with high
spectral time resolution at dm-cm wavelengths by patrol instruments;
and at hard X-rays. The event appears to be build up by a first major
injection of softer particles followed by other injections of harder
particles. Ultrafast time structures were identified as superimposed
to the burst emission at the cm-mm high sensitivity data and at X-rays,
with predominant repetition rates ranging 2.0 - 3.5 Hz.
---------------------------------------------------------
Title: A torsional wave model for solar radio pulsations.
Authors: Tapping, K. F.
1983SoPh...87..177T Altcode:
One of the widely accepted models for solar radio pulsations invokes
radial oscillations of a magnetic flux tube. Due to acoustic, radiative
damping, this theory does not easily explain the long length of the
pulse trains, the large modulation depths or the great stability of
the pulse repetition rate often observed. Torsional waves efficiently
modulate synchrotron emission, and since they do not undergo radiative
damping, can produce stable pulse repetition rates and long pulse
trains.
---------------------------------------------------------
Title: VLBI of solar flares
Authors: Tapping, K. F.; Kuijpers, J.; Kaastra, J. S.; van Nieuwkoop,
J.; Graham, D.; Slottje, C.
1983A&A...122..177T Altcode:
From April 28 to May 3, 1981, a VLBI experiment was carried out
to observe small spatial scales in the initial energy release
in solar flares. The 25 m radio telescope at Onsala (Sweden) and
Dwingeloo (Netherlands) were used; the observing wavelength was 18
cm. Simultaneous observations were made using the Westerbork Synthesis
Radio Telescope at a wavelength of 6 cm. The VLBI baseline was 619
km. During the observing period, three weak outbursts were observed,
none yielding any strong correlated signals. However, the statistical
behaviour of the correlator output over the range of delay channels
shows significant indications of a correlated signal having a signal
to noise ratio of order unity, during the impulsive spikes preceding
the main phase of the event.
---------------------------------------------------------
Title: A Beam Ratio Technique for Microwave Observation of S-Component
Sources
Authors: Tapping, K. F.
1983SoPh...83..179T Altcode:
The fluctuations in the tropospheric attenuation constitute a major
problem when S-component source variations are studied. On records made
by means of `single beam' antenna systems, separating solar variations
from spurious effects can be very difficult. The twin-beam, beam ratio
technique circumvents this problem by deriving a ratio with respect
to a reference beam which is identically affected by the tropospheric
attenuation and by receiver gain variations.
---------------------------------------------------------
Title: Very long baseline interferometry of solar flares
Authors: Kuijpers, J.; Tapping, K. F.; Graham, D.
1983ASSL..102..339K Altcode: 1983ards.proc..339K; 1983IAUCo..71..339K
An experimental VLBI search for the occurrence of subarcsecond
microwave emission centers as tracers of the initial energy release in
solar flares is discussed. The observations extended over the period
April 28 to May 3, 1981, during which period three weak outbursts
occurred. No large correlations were observed, but a strong indication
of an unresolved source with a signal to noise ratio of order unity
was found during the impulsive bursts preceding the main phase of
one event. During the impulsive bursts the spread in number of the
channel which showed the maximum correlation amplitude was reduced
significantly below the value for random behavior. A clear reduction
in the amount of scatter from the expectation value during impulsive
bursts is shown. The derived brightness temperature is of the order 10
to the 12th K; the probable error box for the source position is shown.
---------------------------------------------------------
Title: Combined radio-optical observations of active solar regions
associated with the S-component of solar miocrowave emission.
Authors: Gaizauskas, V.; Tapping, K. F.
1980JRASC..74..358G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Long-lived microwave pulsations observed in a complex solar
active region
Authors: Gaizauskas, V.; Tapping, K. F.
1980ApJ...241..804G Altcode:
Microwave pulsations were detected on Sept. 13, 1977 in the intense
emission from a compact microwave source associated with the large,
slowly rotating, and magnetically complex solar active region, McMath
14943. These pulsations persisted over 5-1/2 hours, with the dominant
repetition rate remaining close to 0.4 Hz; they were not associated with
flare activity. The core of the microwave emission was located over a
plage rather than over the major spot in the region. A mechanism for
the pulsating source is proposed in which radial oscillations in an
arched magnetic flux tube modulate the gyrosynchrotron emission from
high energy electrons trapped in the tube.
---------------------------------------------------------
Title: Persistent Quasi-Periodic Microwave Pulsations from a
Non-Flaring Compact Source in a Complex Active Region
Authors: Gaizauskas, V.; Tapping, K. F.
1980BAAS...12..515G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The February 1979 Solar Eclipse on Short Wave
Authors: Wiest, Chip; Tapping, Ken
1980JRASC..74L..40W Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Location of compact microwave sources with respect to
concentrations of magnetic field in active solar regions
Authors: Gaizauskas, V.; Tapping, K. F.
1980IAUS...91...33G Altcode:
From September 1977 to July 1979, 28 active regions with compact
microwave sources were examined by joint optical and radio
observations. In 11 of the 28 observed regions, the compact microwave
sources varied in intensity with time-scales from minutes to several
hours by as much as 50%, neglecting obviously impulsive events. The
brightness temperatures of the sources at 2.8 cm were in the range
30,000 to more than 10 million K; for six sources, the brightness
temperatures exceeded 2 million K. The results cannot be explained in
terms of thermal emissive processes.
---------------------------------------------------------
Title: Detection of a Compact Microwave Source in an Emerging
Active Region
Authors: Gaizauskas, V.; Tapping, K. F.
1979BAAS...11..420G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Ottawa Centre's Radio Telescope
Authors: Tapping, Ken
1979JRASC..73L..12T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Meter wavelength pulsating bursts during the May 21, 1072,
solar noise storm.
Authors: Tapping, K. F.
1978SoPh...59..145T Altcode:
During the May 21, 1972, noise storm, flux density measurements
were made, at a frequency of 140 MHz, of 14 pulsating bursts. These
comprised trains of up to 20 pulses, having pulse repetition rates of
up to 15 s<SUP>−1</SUP>.
---------------------------------------------------------
Title: Amateur Radio Astronomy Part I
Authors: Tapping, K. F.
1978JRASC..72L...5T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Amateur Radio Astronomy Part II
Authors: Tapping, K. F.
1978JRASC..72L..22T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Amateur Radio Astronomy Part III
Authors: Tapping, K. F.
1978JRASC..72L..38T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Amateur Radio Astronomy Part IV
Authors: Tapping, K. F.
1978JRASC..72L..60T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Distribution Of Solar Radio Flux: Levels And Oscillatory
Bursts
Authors: Tapping, K. F.
1976JBAA...87...51T Altcode: 1976JBIS...87...51T
A large collection of regular solar radio measurements conducted over
11 years at six observing frequencies is used to derive models for the
rates of occurrence of type I and type IV events at discrete observing
frequencies. Variations of the occurrence distribution parameter with
frequency are examined, and it is found that normalized flux-density
values have an exponential distribution. A linear relation between
distribution parameter and frequency is obtained for frequencies
above 120 MHz. The observed deviation from this relation below 120
MHz is attributed to the possibility that type I and type IV emissive
centers are no longer optically thick below about 100 MHz. Two typical
examples of oscillatory bursts recorded at 136 MHz are discussed, and
it is suggested that these bursts could be caused by the same mechanism
responsible for type III events; i.e., excitation of coronal plasma
by jets of high-energy electrons produced in the lower corona or the
chromosphere. The origin of the high-energy electrons is considered.
---------------------------------------------------------
Title: Solar and solar system activity.
Authors: Langton, R. J. J.; Smith, J. R.; Tapping, K. F.
1973JBAA...83..138L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Solar and solar system activity.
Authors: Langton, R. J. J.; Smith, J. R.; Tapping, K. F.
1972JBAA...82..379L Altcode:
No abstract at ADS