Page 1
PROGRESS REPORT
THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM
(CONTRACT NAS8-00119)
(for November 2001)
OVERVIEW
The YOHKOH Mission is a program of the Japanese Institute of Space and
Astronautical Science (ISAS) with collaboration by the U. S. National
Aeronautics and Space Administration and the U. K. Science and
Engineering Research Council. The YOHKOH satellite was launched on 30
August 1991 from Kagoshima Space Center (KSC) in Japan. The purpose of
this mission is to study high energy phenomena in solar flares and the
Sun's corona. Under an international cooperative agreement, Lockheed
Martin, under NASA contract, is providing a scientific investigation
using the Soft X-ray Telescope (SXT), one of the primary experiments of
the mission. The SXT was developed at the Lockheed Martin Solar and
Astrophysics Laboratory in cooperation with the National Astronomical
Observatory of Japan, and the Institute for Astronomy of the University
of Tokyo.
MAJOR PROGRAMMATIC ACTIVITIES IN THE MONTH
The RFP for the continuation of the SXT mission through FY02 was
received on 29 November and the proposal response was submitted on 7
December 2001.
SOLAR ACTIVITY
October 29, 2001 - November 11, 2001
In early November, the Sun showed quite high activity levels, but only
produced one X-class flare. It was, however, a princely one and produced a
remarkable particle event. Its best property, though, was that it
occurred in an otherwise undistinguished (but of course beta-gamma-delta)
region with a clear coronal sigmoid. An alert was declared, and within
48 hours the flare took place. There were almost 40 M-class events.
In the latter half of the month, activity was moderate, the background
staying near GOES C1 for the period. There were seven M flares and one
X flare. A sigmoid target of opportunity campaign was declared for
active region NOAA 9704, which subsequently produced a slow C-class LDE
and two M flares (M1.2, M9.9). The events were geoeffective and proton
productive.
At the end of November, the Sun produced another 13 flares M-class and
above. An interesting, and apparently very non-radial, ejective event
was observed on 30-Nov-01, possibly associated with the GOES M1.5 (LDE)
flare starting near 14:00 UT.
CAMPAIGNS
Yohkoh declared an sigmoid alert and supported the subsequent observing
campaign between Nov 3 and Nov 9.
SCIENCE
A solar sunspot group with a hot coronal S-shaped structure ("sigmoid")
is known to have a higher probability of erupting into a coronal mass
ejection. It's therefore one of the tools we are developing for
anticipating dangerous "space weather" events. As the original
statistics suggested, this tool (like all the others!) does not work
perfectly, but... this month it worked like a champ. The SXT Chief
Observer noted a faint but distinct sigmoidal active region, NOAA 9684,
and notified Max Millennium at 7:40 UT on November 3. Then, at 16:20 UT
on November 4, a beautiful energetic flare and CME occurred. A major
geomagnetic storm resulted from the arrival of the flare ejecta and
their interaction with the Earth's magnetic field.
Yohkoh observed four major solar flares in October, after several months
with one or none. The earlier two X-class flares of the four occurred
on the same day (October 19) and in the same active region
(unusual). The next two October events occurred a different region,
though, at 20 degrees south latitude (October 22 and 25). This is a new
rotation of the "active region complex" seen previously (X-flares on
August 25, September 24). From the 17th through the 29th of October,
this region complex made its fourth disk passage, and its eastern part,
NOAA 9672, produced two X-class flares on the 22nd and 25th. Normally a
solar active region will make major flares early in its life, and then
settle down a more sedate existence (but still possibly capable of
coronal mass ejection). In this case a veteran complex of activity
demonstrated again that the occurrence of activity is far from a random
process; on its fourth rotation this complex still found enough emerging
flux (we believe) to fire off two X-class flares. It is presumably an
example of an active longitude.
PUBLICATIONS
Submitted:
P. Kaufmann, J.-P. Raulin, A. M. Melo, E. Correia, J. E. R. Costa,
C. G. Gim'nez de Castro, A. V. R. Silva, M. Yoshimori, H. S. Hudson,
W. Q. Gan, D.E. Gary, P. T. Gallagher, H. Levato, A. Marun and
M. Rovira, "Solar Submm and Gamma-ray Burst Emission", submitted to ApJ
(2002).
"Solar Submm and Gamma-ray Burst Emission", P. Kaufmann1, J.-P. Raulin,
A. M. Melo, E. Correia, J. E. R. Costa, C. G. Gim?nez de Castro,
A. V. R. Silva, M. Yoshimori, H. S. Hudson, W. Q. Gan, D.E. Gary,
P. T. Gallagher, H. Levato, A. Marun and M. Rovira (ApJ).
Accepted:
"Persistent Coronal Streamers and the Identification of Sunspot
Clusters" by Li, LaBonte, Acton and Slater (ApJ, Feb 1 2002 issue)
Cliver, E. W., and Hudson, H. S., "CMEs: How Do the Puzzle Pieces Fit
Together?" S-RAMP proceedings, Journal of Atmospheric and
Solar-Terrestrial Physics, accepted (2001).
Sturrock, P.A., Weber, M., Wheatland, M.S., & Wolfson, R. 2000,
Metastable magnetic configurations and their significance for
coronal mass ejections. ApJ, in press.
Wolfson, R., Roald, C.P., Sturrock, P.A., Lemen, J., & Shirts, P.
2000, Temperature Structure of the Quiet Corona: an SXT-SUMER
Discrepancy, ApJ, in press.
Published:
"Observing coronal mass ejections without coronagraphs," H. Hudson and
E. Cliver, JGR 26, 25,199, 2001
H. Hudson and E. Cliver, "Observing Coronal Mass Ejections Without
Coronagraphs", JGR 26, 25, 199 (2001).
B. De Pontieu, P. C. H. Martens, and H. S. Hudson, "Chromospheric
Damping of Alfv'en Waves", ApJ 558, 859 (2001).
Roald, C.B., Sturrock, P.A., Wolfson, R. 2000, Coronal Heating:
Energy Release Associated with Chromospheric Magnetic Reconnection,
ApJ, 538, 960.
Wheatland, M.S., Sturrock, P.A., & Roumeliotis, G. 1999, An
optimization approach to reconstructing force-free fields, ApJ,
540, 1150.
Wolfson, R., Roald, C.P., Sturrock, P.A., and Weber, M. 1999,
Coronal X-ray brightness and photospheric magnetic field: A study in
correlations, ApJ, 539, 995.
PUBLIC USE OF SXT IMAGES
We are continuing to make Yohkoh/SXT images available for a variety of
uses. Efforts continue to make selected images available on the LMSAL
SXT WWW homepage (http://www.lmsal.com/SXT/). We receive requests for
the Yohkoh posters (#2 and #3) by way of the form on the SXT homepage.
Currently we receive requests via our homepage at the rate of 2 or 3 per
day. The WEB access statistics in November were 168495 accesses and
13,034 Mbytes transferred for the SXT website and 204118 accesses and
5,017 Mbytes transferred for the YPOP website.
YOHKOH OPERATIONS AND HEALTH
Yohkoh and the SXT continue to function very well.
SXT experienced a normal level of Single Event Upset (SEU) events during
the month:
Warm Reset Error 09-Nov-01 Pass 3: 011109-0206
Recovered in the next pass.
Unknown Error 22-Nov-01 Pass 3: 011122-1238
Recovered 011124-1135
Warm Reset Error 24-Nov-01 Pass 3: 011124-1135
Recovered in the next pass.
Bit Map Error 28-Nov-01 Pass 1: 011128-0927
Recovered in the sa,e pass.
We emerged from the Leonids unscathed, no encounter was detected.
On 22 November an SEU caused SXTE-U to hang up. This occurred during
SAA at approximately 16:27 UT, and strangely enough there was no error
flag. Yobi-B was commanded at approximately 15:27 UT on 24-Nov, and a
recovery plan was carried out throughout the next three KSC passes.
Afterwards, the instrument is operating nominally.
Page 4
DATA FLOW
Month Full Frame Images Observing Region Images
Received Lost Received Lost Loss %
QT FL Tot
Thru Aug-99 640271 233631 2571110 676356 3247466 1142743 25.91
Sep-99 5768 2011 21890 3434 25324 10846 29.99
Oct-99 5768 2308 22994 10487 33481 11517 25.59
Nov-99 7552 3425 20754 18772 39526 11974 23.25
Dec-99 7488 2791 22047 5354 27401 10663 28.01
Jan-00 5426 1736 19802 4040 23842 8958 27.31
Feb-00 6533 2052 21801 7017 28818 8982 23.76
Mar-00 6447 2007 22692 21914 44606 11192 20.06
Apr-00 6412 2100 31195 7214 38409 13438 25.92
May-00 6995 1556 28175 14961 43136 8967 17.21
Jun-00 7043 1722 24413 16369 40782 8690 17.57
Jul-00 6674 1920 23505 31739 55244 10235 15.63
Aug-00 9623 1996 20925 1197 22122 6577 22.92
Sep-00 8835 2240 22233 5764 27997 8307 22.88
Oct-00 6348 1524 23309 6629 29938 7916 20.91
Nov-00 6525 1639 20087 10318 30405 6972 18.65
Dec-00 6585 1918 20718 5422 26140 8071 23.59
Jan-01 5610 1231 20469 3161 23630 7317 23.64
Feb-01 6917 1497 25366 1144 26510 7871 22.89
Mar-01 6851 1272 26315 17139 43454 9470 17.89
Apr-01 5531 1804 15991 20001 35992 9216 20.39
May-01 7410 1758 21042 1767 22809 7152 23.87
Jun-01 7037 1024 24643 5760 30403 5075 14.30
Jul-01 7184 1805 19361 1340 20701 6358 23.50
Aug-01 6741 1443 25710 17252 42962 9100 17.48
Sep-01 4485 1149 16581 24919 41500 7277 14.92
Total 808059 279559 3133128 939470 4072598 1364884 25.10
Number of Full Frame Images Received: 808059
Number of Observing Region Images Received: 4072598
Total: 4880657
Approximate Number of Shutter Moves/CCD Readouts: 8315062
NOTES: * The loss of images is mainly due to BDR overwrites, but there are also
occasional DSN dumps which are lost.
* It is common to have observing regions which contain more than 64
lines, which requires multiple exposures to make a single observing
region image. This is why the number of shutter moves is larger
than the number of images received plus those lost.
Page 5
ENGINEERING SUMMARY TABLE
Month Avg Dark Level # of Dark Spikes CCD Warmings Front Optical (DN) (e/sec) Over 48 Over 64 High / # Support Trans
Temp /Days Temp (%)
Sep-99 60.04 1107.3 231585 49084 21.8 N/A
Oct-99 59.66 1092.9 229735 45263 22.8 N/A
Nov-99 59.90 1102.0 231288 47102 23.0 N/A
Dec-99 60.55 1126.3 233523 53920 22.5 / 2 25.3 N/A
Jan-00 60.27 1115.9 233820 50214 23.4 N/A
Feb-00 60.93 1140.6 235079 56836 23.8 N/A
Mar-00 60.72 1132.8 234174 54661 22.9 N/A
Apr-00 61.10 1147.0 235252 58348 22.2 N/A
May-00 61.00 1143.1 234569 57445 21.2 N/A
Jun-00 61.19 1150.3 235622 58946 22.8 N/A
Jul-00 61.96 1179.3 238114 66905 19.3 N/A
Aug-00 61.27 1153.4 236108 59965 56.9 / 2 21.7 N/A
Sep-00 61.08 1146.2 235644 58449 22.1 N/A
Oct-00 61.44 1159.5 237142 61667 23.1 N/A
Nov-00 60.99 1142.7 235849 57271 24.2 N/A
Dec-00 61.59 1165.2 237454 63656 23.8 / 2 21.8 N/A
Jan-01 61.64 1167.3 238962 62922 22.2 N/A
Feb-01 61.84 1174.6 239218 65324 23.5 N/A
Mar-01 61.89 1176.7 239128 65898 23.1 N/A
Apr-01 61.92 1177.5 239784 66169 22.6 N/A
May-01 62.25 1189.9 240631 69412 22.8 N/A
Jun-01 62.17 1187.1 240572 68588 21.6 N/A
Jul-01 62.75 1208.8 241519 74670 22.5 / 2 22.7 N/A
Aug-01 62.77 1209.6 241443 75645 22.3 N/A
Sep-01 62.51 1199.9 240909 72766 22.2 N/A
NOTES: * The dark current calculations are using full half resolution 2.668 sec
images not taken in during the SAA. The dark current rate assumes a
"fat zero" of 30.5 DN and a gain of 100 e/DN.
* The entrance filter failure of 13-Nov-92 eliminated the capability of
taking optical images, so the optical transmission is not available
after Nov-92. It also caused an increase in the dark current signal,
however some of the increase shown here is an increase in the readout
noise and is not a function of exposure duration.
Page 6
PERSONNEL TRAVEL
SXT Foreign Travel between 1-NOV-01 and 30-NOV-01
BARTUS 1-NOV-01 * 30-NOV-01 * 30
(total of 30 days)
HUDSON 2-NOV-01 13-NOV-01 12
(total of 12 days)
MCKENZIE 14-NOV-01 30-NOV-01 * 17
(total of 17 days)
SATO 14-NOV-01 30-NOV-01 * 17
(total of 17 days)
TAKEDA 1-NOV-01 * 30-NOV-01 * 30
(total of 30 days)
----------------------------------------------------------------
Grand Total of 106 days for 5 people
NOTE: The "*" signifies travel that actually ends after 30-NOV-01
SXT Foreign Travel between 1-DEC-01 and 31-DEC-01
BARTUS 1-DEC-01 * 18-DEC-01 18
(total of 18 days)
HUDSON 18-DEC-01 28-DEC-01 11
(total of 11 days)
MCKENZIE 1-DEC-01 * 14-DEC-01 14
(total of 14 days)
SATO 1-DEC-01 * 31-DEC-01 * 31
(total of 31 days)
TAKEDA 1-DEC-01 * 29-DEC-01 29
(total of 29 days)
----------------------------------------------------------------
Grand Total of 103 days for 5 people
NOTE: The "*" signifies travel that actually ends after 31-DEC-01
Respectfully submitted,
Thomas R. Metcalf
Frank Friedlaender
Page 7
=================================================================
Montana State Univ Activity Report for October-November 2001
=================================================================
(R. Canfield)
INTRODUCTION
The MSU group carried out SXT operations, data analysis, graduate and
undergraduate research, participated in meetings, and performed outreach
activities.
We are pleased that the SXT/Yohkoh funding for the next 2 years won't be
worse than it is. At the same time we're sorry that our hopes to
continue strong theory work by SXT Co-I's and support of dedicated
observing in Hawaii was not possible under the Senior Review 2001
priorities.
YOHKOH AND SXT OPERATIONS
Yohkoh health remains good and operations normal.
McKenzie and Sato spent the second half of November at ISAS for Yohkoh
operations. Sato spent this time learning the tasks of SXT Chief
Observer. On the basis of observations of the presence of an X-ray
sigmoid near disk center, they orchestrated a successful Sigmoid Target
of Opportunity observing campaign within days of their arrival. They
wrote an SXT Nugget about their results:
http://solar.physics.montana.edu/nuggets/2001/011130/011130.html
RESEARCH
Acton worked on drafts of a couple of papers on X-ray irradiance:
"Solar Extreme Ultraviolet and X-ray Irradiance Variations"
Tom Woods, Loren Acton, Scott Bailey, Frank Eparvier, Howard
Garcia, Darrell Judge, Judith Lean, Don McMullin, Gerhard
Schmidtke, Stan Solomon, Kent Tobiska, and Rodney Viereck,
for the ISCS 2001 book (AGU Monograph).
"The Relationship Between X-ray Radiance and Magnetic Flux"
Alexei A. Pevtsov, George H. Fisher, Loren W. Acton, Dana W.
Longcope, Christopher M. Johns-Krull, Charles Kankelborg, and
Thomas R. Metcalf, to be submitted to ApJ Letters.
Acton is undertaking X-ray bright point radiance measurements from SXT
for comparison with the EIT-derived results currently quoted in the
second of these papers. With McKenzie, Acton spent some time attempting
to understand the reason for invalid AlMg/Al12 ratios in faint features
in connection with McKenzie's coronal downflow work. The correction for
x-ray scatter is crucial in this situation and the standard software
isn't good enough. Finally, Acton is back working on achieving
definitive background and straylight correction for our nascent SSC
database. Thanks to Davey we have a shiny new 2+ Tb disk farm and a
fast dual cpu processor for this effort -- and all of the mission-long
Yohkoh database is now online at MSU.
McKenzie worked with Dana Longcope on a 3D model of a postflare arcade
and closed out the month immersed in SXT image cleaning and data
preparation, to attempt temperature analysis of a spikey arcade with
supra-arcade downflows. For this purpose he continued to work on the
SXT point spread function, trying to remove the effects of scattering
from the images (see Acton's report above). He found a bug in
SXT_PSF.PRO, which will be corrected in SSW. A bigger problem is trying
to estimate the amplitude of the scattering wings of the PSF. For
example: pick an area in the flare image where you believe the signal is
due only to scattering (like on-disk region for an over-the-limb flare).
Adjust the amplitude of the PSF wings and deconvolve, until the signal
in the box is consistent with zero. This works, but the required
amplitude is unreasonably big. Still working on it, now experimenting
with the slope of the scattering wing (heretofore have assumed
inverse-square radial dependence).
Canfield started a project with undergraduate Zachary Blehm, McKenzie,
and postdoc Bob Leamon on the quantitative measure of the size and shear
angle of sigmoids in SXT SFD images. The goal of this project is to
obtain a quantitative measure of the non-potentiality of the corona of
active regions based exclusively on X-ray imaging. Canfield also worked
on a manuscript describing a project done with Alex Pevtsov and former
MSU graduate student Andy Burnette. In this project, several tens of
SXT images were fit with linear force-free extrapolations of NSO/KP
magnetograms, and the resulting values of the force-free-field parameter
alpha were compared to independent values derived from Mees HSP vector
magnetograms. Systematic differences are seen, but not yet understood.
Visiting graduate student Szymon Gburek and Martens made dramatic
progress with the in-orbit determination of the SXT PSF when they got
the Blind Iterative Deconvolution code to work. Next they have to
introduce a reasonable apodization function, but that is relatively easy
and arbitrary, and then they'll compare the Moffat fits of the in-orbit
determined PSF for 2000 with the pre-launch calibrations done at White
Sands. The code will also produce cleaned up images, and can be applied
to images from any orbiting solar telescope. Martens and MSU graduate
student Jonathan Cirtain started preparing a revolutionary paper on
coronal loop thermal structure, based on Jonathan's JOP 146 data of last
month.
Sato mainly improved the MSU on-line SXT/HXT flare database. He added a
HXT and GOES light curve plot and position and spectral information
derived from HXT. The spectral information is composed of Te (derived
from the ratio of the M1/L channels of HXT) and gammas (slopes derived
from the ratios of the M1/L, M2/M1, and H/M2 channels of HXT).
SERVICE AND OUTREACH
Martens reviewed proposals and participated in a NASA review panel.
Canfield reformatted the SXT Chief Observer's weekly reports at
http://solar.physics.montana.edu/nuggets/ and mirror sites at Lockheed,
ISAS, and MSSL. McKenzie helped some high school students in Taiwan
find their way to SXT images for an analysis project they're tackling,
and understand the difference between HXT and SXT. He also helped a TV
producer from The Netherlands to locate some movies of solar flares and
provided SXT SFD images to a museum curator in California. He
maintained and updated the SXT website and gave a presentation about the
Sun and the MSU Solar Group to a seminar of Film School master's
students. At least two of the students are interested in producing a
short documentary about solar science and/or grad studies. He gave a
seminar to the Space Public Outreach Team (SPOT), which is sponsored by
NASA Space Grant; he presented solar movies and explanations thereof to
a very receptive bunch of student "outreachers".
PUBLICATIONS:
Talks Given:
------------
"The Sun Studied from Space: How the Sun Influences the Earth", P.
Martens, EdPARc meeting, Bozeman, October 9, 2001.
"Solar Max: What and Why", R. C. Canfield, Rose City Astronomers, Oregon
Museum of Science and Industry, Portland, October 15th, 2001.
"Origin and Evolution of Filament-Prominence Systems", P. Martens,
Relativity/Astrophysics seminar, Montana State University, November 1.
=============================================================
Univ of Hawaii Activity Report for October-November 2001
=============================================================
(J. Li)
- Major Activities for October and November 2001:
Our activities included support of Yohkoh operations and data analysis
at ISAS, coordinated ground-based data acquisition (including designated
Yohkoh campaigns) at Mees, collaborative analysis of Yohkoh/Mees data,
and preparation of manuscripts.
Operational support for SXT was provided by G. Nitta at Mees and LaBonte
and Li in Manoa.
Our colleagues, Canfield at Montana State University, Wuelser and
Metcalf at Lockheed, and Hudson at Solar Physics Research Corporation
aided in advice and oversight of Mees operations.
LaBonte has relocated to Johns Hopkins University, Applied Physics Lab.
He will continue to have a daily role in overseeing Mees operations and
data analysis.
Weather at Mees was average during the October and November. The
observations were carried for 65% scheduled days in October and 57% in
November. The total coverage was limited by the number of vacations and
holidays and the leave of the observer.
The Sun had numerous active regions, but lacked major events during the
two months of period. Only 3 of the 15 flares >M5 class occurred during
Mees observing hours, and we obtained good data for two, an X1 on
22-Oct-2001 at 17:44 in AR9672 and an M9 on 22-Nov-2001 at 22:32 in
AR9704.
Li visited Chinese National Observatory in Beijing in October. She
worked with Dr. Zhang to finish the manuscript "Analysis of Vector
Magnetic Field in Solar Active Regions by Huairou, Mees and Mitaka
Vector Magnetographs". Dr. Zhang will submit the paper after LaBonte
revises it.
Li is working on Mees IVM data for the period of 1996-1997 in order to
understand the magnetic properties of sunspot clusters which are
identified in her latest paper, "Persistent Coronal Streamers and the
Identification of Sunspot Clusters" by Li, LaBonte, Acton and Slater
(ApJ, Feb 1 2002 issue).
============================================================
Stanford Univ Activity Report for October-November 2001
============================================================
(P. Sturrock)
Peter continues to collaborate with Jim McTiernan in Berkeley concerning
the optimization-function approach to the reconstruction of force-free
magnetic field configurations from photospheric vector magnetograph
data. The optimization-function method rests on the minimization of the
integral of a sum of terms, each term being the square of the error in
each relevant equation (the divergence equation and the force
equation). Jim is currently converting his code from C to IDL. This is
proceeding well, but is taking longer than expected, since a lot of bugs
crept into the program during the conversion process. However, when
converted to IDL, the program should be more convenient for graphics
output and for comparison with data. For more information, see the UC
Berkeley contribution to this report.
Mark and Peter are beginning a new project. For several years, Peter has
been studying solar neutrino data, with several collaborators, and with
support from other grants. These studies have yielded strong evidence
that the solar neutrino flux varies in time. A major component of the
variation is associated with solar rotation. In view of these positive
results, we have decided to review some earlier claims that the solar
neutrino flux is correlated with coronal emission. The earlier studies
utilized data from ground-based green-line coronagraphs. SXT provides
greatly superior data, and has now been running long enough that it
seems reasonable to compare the SXT time series with the neutrino time
series. We expect that there will be a correlation, but - if there is -
the big question will be whether the correlation is due simply to the
fact that both time series show rotational modulation, or whether there
is evidence that coronal emission responds to the same subsurface
magnetic structures that we believe to be responsible for rotational
modulation of the neutrino flux. It is too early to report any results
on this project.
To continue his time-series analysis of latitudinally binned SFD (SXT,
processed, whole-Sun) images, Mark has implemented Bayesian analysis
techniques as IDL code. Under the typical Fourier model wherein the
time-series (in this case, the logarithm of the SXT intensity) is
represented as a linear combination of sinusoids, this evaluation finds
the best fit. Here, "best" means finding an optimal balance between
restricting the number of degrees of freedom in the model and accounting
for much of the variance in the data set. Applying the code to the
60-degree S bin, we find that the strongest periodicity is the solar
cycle, the second largest is around 1.3 yrs, and the solar rotation is
third. The 1.3 yr signal is intriguing because it matches an
oscillation in rotation frequency at the tachocline, as reported by the
SOHO/MDI Team (Howe et al, 2000, Sci 287, 2456). If this correlation
turns out to be robust under further investigation, it would provide
further evidence that large-scale coronal fields may be rooted deeply in
the solar convective zone.
PUBLICATIONS
Roald, C.B., Sturrock, P.A., Wolfson, R. 2000, Coronal Heating:
Energy Release Associated with Chromospheric Magnetic Reconnection,
ApJ, 538, 960.
Sturrock, P.A., Weber, M., Wheatland, M.S., & Wolfson, R. 2000,
Metastable magnetic configurations and their significance for
coronal mass ejections. ApJ, in press.
Wheatland, M.S., Sturrock, P.A., & Roumeliotis, G. 1999, An
optimization approach to reconstructing force-free fields, ApJ,
540, 1150.
Wolfson, R., Roald, C.P., Sturrock, P.A., Lemen, J., & Shirts, P.
2000, Temperature Structure of the Quiet Corona: an SXT-SUMER
Discrepancy, ApJ, in press.
Wolfson, R., Roald, C.P., Sturrock, P.A., and Weber, M. 1999,
Coronal X-ray brightness and photospheric magnetic field: A study in
correlations, ApJ, 539, 995.
===========================================================================
Solar Physics Research Corp. Activity Report for October-November 2001
===========================================================================
(Karen L. Harvey and Hugh S. Hudson)
KAREN L. HARVEY:
Activities for October and November:
(1) Continuing with a comparison of the coronal holes identified in
NSO/KP He I 10830 rotation maps and with corresponding Yohkoh/SXT
rotation maps to determine if the structures identified as coronal holes
in He I 10830 all are associated with low emission areas.
A program has been written to view coronal hole boundaries superimposed
on the synoptic He I 10830 spectroheliograms, magnetograms, and SXT
images to better follow coronal holes, their formation and evolution.
Isolated coronal holes appear to form in a specific magnetic field
configuration; we are examining whether this a sufficient and/or
necessary condition.
(2) Continued the analysis of the 18 December 1998 HAO/CHIP He I 10830
data in collaboration with Terry Forbes to measure the magnetic flux as
a function of time within an area bounded by the flare ribbons and the
polarity inversion separating them and within the associated transient
coronal holes. The objectives of this study are to determine the
reconnection rate of a flare and as an addendum to our original goal, to
investigate the role of the transient coronal holes in the accompanying
CME.
We find a two part structure to the distribution of He I 10830
equivalent width within the bounds of the transient coronal holes. We
are trying to determine the validity of this finding by using a
threshold to differentiate between the supposed two part structure.
Plans for December and January:
Continued analysis (1) of the association of coronal holes observed in
He I 10830 spectroheliograms and the SXT full-frame and synoptic images;
this includes isolated, non-polar coronal holes, as well as the
transient coronal holes; of particular interest is the formation of
coronal holes and of polar extensions; (1) with T. Forbes of the
reconnection rate of magnetic fields during long-duration arcade
events/He I 10830 2-ribbon flares and comparison of the transient
coronal holes with X-ray/EUV dimmings; (3) return to a collaborative
project with Keith Strong on the solar cycle variation of XBP started in
1995 for a paper presented the 1996 Bath meeting.
HUGH S. HUDSON
Activities for October and November:
Main activities included some work on white-light flares, in support of
Sarah Mathews's Y10 paper. Why are people no longer really fascinated
with white-light flares? There seems to be almost no current literature
except from China, and yet this phenomenon really remains one of the
toughest-to-explain aspects of flare physics. Please recall that the
initial work with the best few SXT white-light observations more or less
confirmed ideas based on close timing relationships between WL and hard
X-rays. But there is an additional slower component; presumably this is
even harder to explain because the excitation may be less non-thermal
somehow. Accordingly, I estimated the coronal gas pressure for the 28
events on the list of probable WLF detections (list originally compiled
by Lidia Van Driel-Gesztelyi, I think), and for a similar list of other
events. As expected, the WLF's have higher coronal pressures (in
extreme cases, such as 1991 Dec. 3, exceeding 1000 cgs - a memorable
day), and the time variation of coronal gas pressure has a slower, later
development than the hard X-rays. But what mechanism is at work?
Other topics included the May 6 wave paper, almost ready now. Joe Khan
completed a ray-tracing analysis, which we think provides the first
authentic (within errors, of course) determination of the radiant point
and time for one of these waves. We find its origin not to match the
flare core loops very well, either spatially or temporally.
I also helped Franta Farnik with his new hard X-ray data, trying to get
an empirical cross-calibration against HXT. This work is not finished
yet, but in the meanwhile the October 24 event (written up in a nugget)
offered us a tantalizing look at hard X-ray emission from the earliest
stages of an X-class flare. The hard X-rays in this case were
accompanied by a swarm of decimetric spike bursts. This was also the
subject of ISAS seminar talks on October 11.
Reviewing Markus Aschwanden's massive review for Space Science Reviews
consumed a fair fraction of my research time. How can somebody write
faster than you can read? Since Markus and I are both members of this
august forum, everybody will appreciate the breadth of this comment.
I'd just like to thank ADS for making it so easily possible to look up
original sources while reading; it is enough to make one prefer the
flickering screen to the solid tome.
A seminar given at UC Berkeley dealt with observations and implications
of the presence of open field lines in the solar corona. Non-auditors
are probably lucky here, since the HTML version (
http://isass1.solar.isas.ac.jp/~hudson/talks/berkeley.011120 ) may be a
lot more intelligible than the spoken word! This is another subject
(see also flare/CME relationships) in which high-energy particles must
be understood in the same breath as coronal MHD. Not easy!
Another seminar,
http://isass1.solar.isas.ac.jp/~hudson/talks/isas.011108, covered the
white-light flare analysis reported last month. In the same vein Tom
Metcalf, David Alexander and I continued the analysis of the white-light
flare reported in SXT science nugget
http://isass1.solar.isas.ac.jp/sxt_co/010831.html which will be
presented as a poster at the AGU Fall meeting.
Plans for December and January:
The main December activities will be preparing for AGU, including an
oral presentation on non-thermal electrons within CMEs plus a poster
with Fletcher on theory and modeling of same. This work includes a
further effort to survey for coronal hard X-ray sources from extreme
over-the-limb events, but with limited success.
In January I plan to visit the Santa Barbara and Yohkoh 10 workshops,
but the main effort will be the same item mentioned in several (most?)
of the last dozen reports of this type. Alert reader will know.
PUBLIC SERVICE: Refereeing for the FWF (Austria), GRL, ApJ, Space
Science Reviews; help with Yohkoh science nuggets; additions to the
cartoon archive.
PUBLICATIONS
Papers Submitted:
P. Kaufmann, J.-P. Raulin, A. M. Melo, E. Correia, J. E. R. Costa,
C. G. Gim'nez de Castro, A. V. R. Silva, M. Yoshimori, H. S. Hudson,
W. Q. Gan, D.E. Gary, P. T. Gallagher, H. Levato, A. Marun and M. Rovira,
"Solar Submm and Gamma-ray Burst Emission", submitted to ApJ (2002).
Papers Accepted:
Cliver, E. W., and Hudson, H. S., "CMEs: How Do the Puzzle Pieces Fit
Together?" S-RAMP proceedings, Journal of Atmospheric and Solar-Terrestrial
Physics, accepted (2001).
Papers Published:
H. Hudson and E. Cliver, "Observing Coronal Mass Ejections Without
Coronagraphs", JGR 26, 25, 199 (2001).
B. De Pontieu, P. C. H. Martens, and H. S. Hudson, "Chromospheric Damping
of Alfv'en Waves", ApJ 558, 859 (2001).
TAKEDA AKI:
Activities for October and November:
I worked the following four weeks as an SXT_CO or a Yohkoh operator.
week 43 (22-Oct through 28-Oct): SXT_CO
week 44 (29-Oct through 4-Nov): SXT_CO
week 46 (12-Nov through 18-Nov): SXT_CO
week 47 (19-Nov through 25-Nov): Yohkoh operator at SSOC
During the week 43, I cooperated with three campaigns; the TRACE/Sac
Peak campaign through the week, a VLA campaign and SOHO JOP 149 for a
few days each. In week 44, I declare the sigmoid campaign on 3rd
through 9th Nov. This region fortunately produced an X-flare on the 4th
with a strong proton events accompanied.
In the week 47, SXT had stopped observation without showing any error
flag on 22nd Nov. The condition was analyzed by H. Hara and SXT_COs,
and they found that the SXT-U unit returned no response. The hard reset
command followed by a recovery plan was tried on the 24th. I, together
with SXT_COs (D. McKenzie and J. Sato) and H. Hara, remotely observed
the real-time operation at Kagoshima station around mid-night. The SXT
finally resumed normal observation after those procedures.
In the afternoon on 14th November, several graduated students of Meisei
University visited ISAS with Prof. T. Hirayama as a leader. I gave them
a short presentation on the whole Yohkoh mission and the SXT project and
showed them inside ISAS.
To the following editions of the science nuggets, I made full or partial
contribution.
http://isass1.solar.isas.ac.jp/sxt_co/011012.html "Life story of a super
region complex", describes the enhanced flare activity observed from
mid-August through late-September. It was mainly brought by an active
region complex, which appeared at around 20 degrees in the south in this
period.
http://isass1.solar.isas.ac.jp/sxt_co/011026.html "A swirling X-class
flare". A brief report of the X-class event on 19th Oct., observed with
SXT. Most description was done by H. Hudson, and my contribution is the
creation of the composite movie.
http://isass1.solar.isas.ac.jp/sxt_co/011102.html "A veteran complex of
activity, still alive and kicking" A large complex of activity that we
had nuggetized before (011012.html) revived, an active longitude
revealing itself, to produce X-class flares.
http://isass1.solar.isas.ac.jp/sxt_co/011109.html "Sigmoid success: a
CME predicted" documents the November 4 event, listing 8 or 9 remarkable
characteristics; the one that pleased us most, of course, was its
obedience to the pattern of sigmoid region eruption. But the
interplanetary particle event was a GLE and a "snowstorm" on SOHO of
blinding intensity.
http://isass1.solar.isas.ac.jp/sxt_co/011116.html "A skinny but robust
coronal hole", reports on a coronal hole observed extending from the
north pole at the end of October through early November.
JANOS BARTUS
Activities for October and November:
pollux:
- registering pollux on the RedHat network (https://rhn.redhat.com/)
- full OS update: more than hundred packages were updated, new kernel
compilation
- replacement of the failed power supply
- proftp server update
- ssh update on pollux
- DAC1100 RAID card's kernel module update
isass0/1/5:
- registering isass0/1 on the RedHat network
- package updates
- failed disk in the RAID5 system on isass0 - alert disabling
- proftp server update on isass0/1
- ssh update on isass0/1/5
others:
- go_go_toban web interface improvements
- moving to the new building A:
arranging furniture, computers,
building network, setting up X terminals,
sorting out sysadmin stuffs etc.
- planning the layout of the new rack for pollux, isass5,
flare 29 and RAID
- lps17 printer software installation on isass5, lps17 can boot now
from isass5
- BigBrother: highly configurable web based monitoring tool
installation on isass1: the status of whole computer system can be
checked on one web page
- windows - linux connectivity: samba
installation and configuration on isass1:
- secured telnet service reenabled on isass0/1/5,pollux
- connecting our subnetwork to ISAS's Gigabit backbone
- nessus security portchecker update and nessus checking for all our
machines, fixing the security holes found
- fixing the ssh communication problem between flare20 and isass5
- setting up the my new sysadmin PC, purchased by ISAS
Plans for December and January, 2001 (2002):
- setting up the new, linux based isass5
- setting up new video server
- setting up rack for pollux, isass5, flare 29, isass0/1's RAID disk
- setting up the CD-backup system on flare29
- UPS protection for all the computers
- preparations for the hawaii meeting
===========================================================================
University of California Activity Report for October-November 2001
===========================================================================
(G. Fisher)
Chris Johns-Krull is continuing to work on the H-alpha linear
polarization data obtained at BBSO. Yohkoh HXT data constrains both the
location and number of accelerated electrons during flares which can be
compared with the H-alpha polarization measurements and upper limits to
test the predictions of proton beam acceleration during flares. The
manuscript is nearing completion. This study and its initial results
were presented in a seminar entitled "H-alpha Linear Polarization
Observations of Solar Flares: The Search for Proton Beams" presented on
Oct. 17, 2001 at Rice University in Houston, TX.
Work was also performed on a paper which appears to show a universal
relationship between magnetic flux and X-ray luminosity on the Sun and
other cool stars. Johns-Krull used his own magnetic field measurements
and the literature to estimate the magnetic flux and X-ray luminosity of
a sample of 5 pre-main sequence stars for comparison with solar and
other stellar data. Fisher and Alex Pevtsov of NSO worked on preparing
an early draft of this paper, which is now circulating among the other
co-authors. There is currently a debate and discussion occurring among
the co-authors on whether X-ray Bright Points fit within the Universal
Relationship or not. We expect this issue to be resolved quickly. The
Paper will be submitted as an ApJ Letter entitled "The Relationship
Between X-ray Radiance and Magnetic Flux" by Pevtsov, Fisher, Acton,
Longcope, Johns-Krull, Kankelborg, and Metcalf.
Fisher and Bill Abbett (also of SSL) have made a major breakthrough in
the development of a 3-D adaptive mesh MHD code, appropriate for the
corona of active regions. We anticipate that this tool will prove of
great use in modeling magnetic structure in active regions, and that
this will greatly aid in the future analysis of SXT images.
Page 6
-------------------------------------------------------------------------------
NASA REPORT DOCUMENTATION PAGE
(IN LIEU OF NASA FORM 1626)
--------------------|--------------------------|-------------------------------
1. REPORT NO. | 2. GOVERNMENT | 3. RECIPIENT'S
DR-01 | ACCESSION NO. | CATALOG NO.
--------------------|--------------------------|-------------------------------
4. TITLE AND SUBTITLE | 5. REPORT DATE
Monthly progress report - for the month of | 10 December 2001
November 2001 |-------------------------------
| 6. PERFORMING ORG
| CODE: O/L9-41
-----------------------------------------------|-------------------------------
7. AUTHOR(S) | 8. PERFORMING ORGANIZA-
T. R. Metcalf | TION REPORT NO:
F. M. Friedlaender |
|-------------------------------
-----------------------------------------------|10. WORK UNIT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS |
Lockheed Martin Missiles and Space |-------------------------------
Advanced Technology Center, O/L9-41, B/252 |11. CONTRACT OR GRANT NO.
3251 Hanover Street, Palo Alto Ca. 94304 | NAS8 - 00119
-----------------------------------------------|-------------------------------
12. SPONSORING AGENCY NAME AND ADDRESS |13. TYPE OF REPORT AND
Marshall Space Flight Center (Explorer Program)| PERIOD COVERED
Huntsville Alabama 35812 | Progress report for the month
Contact: Larry Hill | of November 2001
|-------------------------------
|14. SPONSORING AGENCY
| CODE MSFC / AP32
-----------------------------------------------|-------------------------------
15. SUPPLEMENTARY NOTES
-------------------------------------------------------------------------------
16. ABSTRACT
The SOLAR-A Mission is a program of the Institute of Space and Astronautical
Science (ISAS), the Japanese agency for scientific space activity. The
SOLAR-A satellite was launched on August 30, 1991, to study high energy
phenomena in solar flares. As an international cooperative agreement,
Lockheed, under NASA contract, is providing a scientific investigation and
has prepared the Soft X-ray Telescope (SXT), one of the two primary
experiments of the mission.
--------------------------------------|----------------------------------------
17. KEY WORDS (SUGGESTED BY | 18. DISTRIBUTION STATEMENT
AUTHOR(S)) Solar-A, X-ray, CCD, | Space Science, Solar Physics
------------------------|-------------|----------|-----------------|-----------
19. SECURITY CLASSIF. | 20. SECURITY CLASSIF. | 21. NO OF PAGES |22. PRICE
(OF THIS REPORT) | (OF THIS PAGE) | |
None | None | 19 |
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