Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-40801) (for January 1997) 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, 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 Palo Alto Research 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 Yohkoh has entered its seventh calendar year of operations. The longevity and the scientific legacy of the Yohkoh mission are attributable to many hard- working individuals in Japan, the UK, and in the USA. Important upcoming near-term activities include the securing of funding for operations beyond FY 1997 and preparations for the impending Senior Review. << Solar Activity >> Solar activity continued at a low level during January. The highlight of this period was undoubtedly the remarkable "halo CME" seen by SOHO/LASCO on Jan 6, which led to a geomagnetic storm and possibly to the termination of an ATT communications satellite (quoted as costing $200M) under circumstances somewhat reminiscent of the Anik failures of 1994, perhaps. Yohkoh did not see very much from this event. There was an extremely weak LDE event in an active region on the central meridian, in the southern hemisphere as expected from the off-center bias of the halo CME seen by LASCO. Hugh Hudson analyzed the SXT data for "dimming", loop expansion, and arcade formations but found little evidence for such signatures. A filament disappearance at the right time and place was apparently noted at Ramey and Nobeyama, and so we conclude that the weak LDE in the active region did was responsible. The fact that the soft X-ray signatures were so weak is itself quite interesting scientifically. << Campaigns >> Page 2 A joint observing campaign with SOHO (JOP057) and ground-based observatories resulted in successful observations of polar jets. SXT obtained three sets of long-exposure observations of the north polar hole to support this campaign, guided by S. Koutchmy and H. Hara. These observations coincided with the appearance of a compact, bright active region on the east limb. During 17 - 22 January Yohkoh observed streamers at the east and west limbs in collaboration with SOHO. The campaign was coordinated by Shadia Habbal (CFA). Yohkoh was offpointed 5 arcmins east 17-19 January, and then 5 arcmins west 19-22 January. The bases of streamers were clearly observed in the special long exposure FFI tables we used. On 23 January Yohkoh coordinated with SOHO CDS and LASCO observations of a small set of active loops on the East limb. EIT and LASCO observed a CME on 23 December 1996 and SXT also obtained limited observations of the flare that was associated with this event, but only in the full-frame images and it unfortunately occurred during the time that SXT was obtaining weekly dark calibration images (so there were future X-ray images taken). However, this event brings the Yohkoh/SOHO CME event list to four. For Yohkoh operations, there is a text file accessible on the Web at http://www.space.lockheed.com/SXT/html2/First_Light.html which also lists the current SXT Chief Observer, or the Unix command: # finger campaign@isass0.solar.isas.ac.jp | more The SOHO target planning is available from: http://sohowww.nascom.nasa.gov/operations/targets/today << Science >> The big event at the Lockheed Martin Solar and Astrophysics Laboratory was the Coordinated Data Analysis Workshop (CDAW) on HXT image reconstruction. The workshop was attended by The CDAW was organized by David Alexander and Takeo Kosugi along the lines of the successful series of Yohkoh CDAWs that were held at the University of Hawaii over the past few years. The workshop was a great success. New calibration response functions were incorporated into the MEM and Pixon algorithms. During the workshop, analysis of psuedo data revealed a small mis-estimation of the algorithms in the HXT flux which was quickly repaired. As a result, the reconstructions are more robust and the differences between the various algorithms (Pixon and MEM) are better understood. Tom Metcalf has implemented the improvements in the Pixon code and is looking ways to speed up the code. Plans are being made to generate automatically a "quick-look" version movie of all HXT flares. The report of the workshop can be obtained from the following URL: http://diapason.space.lockheed.com/~alexande/CDAW/nugget.html Nariaki Nitta has revised his superhot flare paper, conducting further analysis and incorporating an H-alpha frame that he obtained from Austria. He finds that the temperature of the superhot plasma, which has a large uncertainty from SXT data alone, doe not exceed 30 MK by very much based on the analysis of his particular event. Nitta is also working with Mukul Kundu on three projects involving X-ray jets and their radio counterparts. Serge Savy worked with Franta Farnik (Czech republic) during his to ISAS on preflare Page 3 brightenings. A short version of this work with appear in the Yoyogi meeting proceedings. Jean-Pierre Wuelser started writing up the material on the Mees IVM observations of polar plumes, obtained in March 1996. At that time, the first coordinated SOHO campaign took place, and the Mees Imaging Vector Magnetograph got a sequence of 41 magnetograms of the South polar region. The data nicely shows the vector magnetic field of plume footpoints, which is unipolar, and closer to vertical than the coronal streamers would suggest. The results were presented at the last SPD meeting, and are now being prepared for publication. << 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 Lockheed SXT WWW homepage (http://www.space.lockheed.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 January were 42770 accesses and 1100 Mbytes transferred. The new SXT video has been received with much acclaim. Keith Strong showed the video to members of the Space Physics Roadmap panel at NASA HQ last month. David Alexander and Tom Berger (another member of the Lockheed Martin Solar and Astrophysics Lab) attended a science fair in San Mateo, CA. They had a small booth with the SXT engineering model and other models of other space-flight instrumentation. Videos and posters were distributed to parents and school children. Tom gave a short talk discussing the magnetic aspects of the solar activity. << Yohkoh Operations and Health >> Yohkoh and the SXT continue to function very well. There has been no further increase in stray light since 25 August 1996. The quiet patrol image has been changed to Al/Mg (DPE=17) to try to improve the performance of the active region selection algorithm for times when the Sun is very quiet. As was done in the past, a "long" spacecraft command load was uplinked on 28 December 1996 to cover the period until 4 January 1997, during which the Yohkoh team was on holiday. During this time Yohkoh mostly operated in medium-rate mode with SXT acquiring 10" (quarter resolution) images. This enabled about a 30% coverage of full-disk observations during this time. During January we performed a routine bakeout of the SXT CCD. SXT experienced a normal level of Single Event Upset (SEU) events during the month: SXT bit map error 21-Jan-97 Pass 1: 970121-1548 Page 4 recovered in pass 1. On 30 January 1997 the SXT table was incorrectly transmitted to KSC during Pass 4 (970130-0102). The recovery was enacted in Pass 5(970130-0205). The problem was caused by operator error on the part of the SXT chief observer trying to send the entire SXT table load instead of just the incremental changes. The full load takes more than one station contact, and this does not permit the SXT tables to be completely updated and thus leaves the SXT in an ill-defined state. Since this particular error has occurred a few times before, it was decided to improve the SXTSPT command software to reduce the potential of this occurrence in the future. After a couple of iterations, the software was updated successfully. Page 5 << Data Flow >> ------------------------------------------------------------------------------ Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Thru Oct-94 252945 111409 1093244 326819 1420063 554020 27.73 Nov-94 6569 1941 26243 1956 28199 9293 24.79 Dec-94 6429 2456 26763 2583 29346 11904 28.86 Jan-95 6870 2349 26103 1699 27802 10211 26.86 Feb-95 6556 2545 23635 3825 27460 10111 26.91 Mar-95 5915 2082 21485 3448 24933 8485 25.39 Apr-95 6244 2266 22946 4493 27439 9688 26.09 May-95 7084 2884 29617 2647 32264 15331 32.21 Jun-95 7210 3087 25251 307 25558 12045 32.03 Jul-95 6418 4145 21180 1639 22819 15109 39.84 Aug-95 7683 2597 26115 2181 28296 10537 27.13 Sep-95 6546 2853 22006 1753 23759 10433 30.51 Oct-95 6937 3502 22177 3853 26030 13044 33.38 Nov-95 5745 2944 21252 517 21769 12119 35.76 Dec-95 6163 2615 24059 901 24960 11652 31.83 Jan-96 6474 2530 27015 1708 28723 14151 33.01 Feb-96 6200 2581 21380 890 22270 10773 32.60 Mar-96 6908 2869 25437 1460 26897 12274 31.33 Apr-96 7172 2124 45445 671 46116 18848 29.01 May-96 6925 2426 30272 1089 31361 12367 28.28 Jun-96 7522 2716 31984 1536 33520 14489 30.18 Jul-96 5954 1995 29886 4769 34655 12427 26.39 Aug-96 7214 3010 21187 1607 22794 9887 30.25 Sep-96 6904 2618 29906 303 30209 12663 29.54 Oct-96 7405 2853 16463 1842 18305 8034 30.50 Nov-96 7001 2296 24292 5395 29687 9340 23.93 Dec-96 5269 2041 18400 1001 19401 7734 28.50 Jan-97 0 0 0 0 0 0 0.00 Feb-97 0 0 0 0 0 0 0.00 Total 426262 179734 1753743 380892 2134635 856969 28.65 Number of Full Frame Images Received: 426262 Number of Observing Region Images Received: 2134635 Total: 2560897 Approximate Number of Shutter Moves/CCD Readouts: 4483719 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 6 << 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 (%) Nov-94 47.64 642.4 70877 4703 20.4 N/A Dec-94 47.82 649.1 74246 4917 21.5 N/A Jan-95 48.55 676.7 89758 5457 20.0 N/A Feb-95 48.70 682.1 92457 5781 25.2 / 3 20.5 N/A Mar-95 48.35 668.9 85527 5271 19.4 N/A Apr-95 48.72 682.8 93904 5627 19.1 N/A May-95 48.73 683.4 94000 5820 18.8 N/A Jun-95 49.08 696.3 100780 6281 19.6 N/A Jul-95 49.34 706.2 106408 6628 18.1 N/A Aug-95 49.72 720.4 114414 7101 19.5 N/A Sep-95 49.79 723.1 115165 7222 19.6 N/A Oct-95 50.29 741.9 126452 7911 20.2 N/A Nov-95 50.11 735.1 122163 7814 25.2 / 2 20.3 N/A Dec-95 50.19 737.9 123705 7927 22.6 N/A Jan-96 50.81 761.3 136197 8888 21.5 N/A Feb-96 50.67 755.8 133263 8705 22.5 / 2 21.5 N/A Mar-96 50.85 762.9 136982 8973 20.3 N/A Apr-96 51.14 773.6 142250 9500 19.9 N/A May-96 51.16 774.4 140697 10018 19.1 N/A Jun-96 51.56 789.2 147705 10634 20.7 N/A Jul-96 57.45 1010.2 146293 12228 19.8 N/A Aug-96 52.58 827.5 165676 12393 19.6 N/A Sep-96 52.47 823.3 162784 12350 20.0 N/A Oct-96 52.21 813.8 157689 12047 22.5 / 2 21.3 N/A Nov-96 52.45 822.9 161683 12534 21.9 N/A Dec-96 53.00 843.2 170047 13658 23.5 N/A Jan-97 N/A N/A N/A N/A 0.0 N/A Feb-97 N/A N/A N/A N/A 0.0 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 7 << Personnel Travel >> SXT Foreign Travel between 1-JAN-97 and 31-JAN-97 CANFIELD 11-JAN-97 24-JAN-97 14 (total of 14 days) HUDSON 1-JAN-97 * 9-JAN-97 9 18-JAN-97 26-JAN-97 9 29-JAN-97 31-JAN-97 * 3 (total of 21 days) NITTA 21-JAN-97 31-JAN-97 * 11 (total of 11 days) SAVY 1-JAN-97 * 31-JAN-97 * 31 (total of 31 days) SLATER 28-JAN-97 31-JAN-97 * 4 (total of 4 days) ---------------------------------------------------------------- Grand Total of 81 days for 5 people NOTE: The "*" signifies travel that actually ends after 31-JAN-97 SXT Foreign Travel between 1-FEB-97 and 28-FEB-97 FREELAND 3-FEB-97 14-FEB-97 12 (total of 12 days) HUDSON 1-FEB-97 * 28-FEB-97 * 28 (total of 28 days) LEMEN 15-FEB-97 28-FEB-97 * 14 (total of 14 days) METCALF 10-FEB-97 28-FEB-97 * 19 (total of 19 days) NITTA 1-FEB-97 * 16-FEB-97 16 (total of 16 days) SAVY 1-FEB-97 * 5-FEB-97 5 19-FEB-97 28-FEB-97 * 10 (total of 15 days) SLATER 1-FEB-97 * 28-FEB-97 28 (total of 28 days) ---------------------------------------------------------------- Grand Total of 132 days for 7 people NOTE: The "*" signifies travel that actually ends after 28-FEB-97 Respectfully submitted, James R. Lemen Frank M. Friedlaender Page 8 ================================================================= Montana State Univ Activity Report for December 1996-January 1997 ================================================================= (L. Acton) INTRODUCTION It has been an unusually cold and snowy winter in Montana. However, neither this nor the holidays have deterred us from our solar research. At the first of the year we were joined by Dr. David McKenzie from Bartol Research Institute and the University of Delaware. McKenzie will concentrate his post-doctoral work on the Yohkoh and YPOP programs. With McKenzie's arrival the MU solar group has reached its full complement, comprising: L. Acton, Res. Prof. R. Canfield, Res. Prof. D. Long-cope, Ass't Prof. A. Pevtsov, Res. Scientist C. Kankelborg, Post Doc D. McKenzie, Post Doc M. Foley, Systems Mgr. & Computer Sci. grad student B. Handy, Grad Student M. Weber, Grad Student B. Welsch, Grad Student D. Weston, Grad Student M. Wills, Grad Student S. Sandborgh, Physics undergrad SCIENTIFIC ANALYSIS and PUBLICATIONS: During the bimester Acton, Bruner and Weston continued work on the problem of the conversion of SXT full-sun observations into x-ray irradiance in arbitrary spectral bands. These measurements are important for studies in aeronomy. Canfield, Pevtsov, Longcope and undergraduate Sean Sandborgh are making good progress on their studies of magnetic helicity. Longcope and grad student Brian Welsch are studying magnetic separators. Grad student Mark Weber is working on solar coronal rotation while Brian Handy continues at Lockheed Martin Solar and Astrophysics Laboratory on the TRACE program. The following papers were submitted or accepted. Pevtsov, A. A., Canfield, R. C., and Zirin, H. ``Reconnection and Helicity in a Solar Flare'', Astrophysical Journal, 473, 533 (1996). Canfield, R. C., Pevtsov, A. A., and McClymont, A. N., ``Magnetic Chirality and Coronal Reconnection'', in Magnetic Reconnection, ed. R. Bentley and J. Mariska, A.S.P. Conf. Series, 111, 341 (1996) Pevtsov, A. A., Canfield, R. C. & McClymont, A. N. ``On the Sub-Photospheric Origin of Coronal Electric Currents'' Astrophysical Journal, in press, June 1 issue, Vol. 481, (1997). Page 9 Li, J., Metcalf, T. R., Canfield, R. C., Wuelser, J.-P., and Kosugi, T., ``What is the Spatial Relationship between Hard X-ray Footpoints and Vertical Electric Currents in Solar Flares?'', Astrophysical Journal, in press, (1997). "Fine Structure of the X-ray and Radio Emissions of the Quiet Solar Corona", A. O. Benz, S. Krucker, L. W. Acton, and T. S. Bastian, Astron. & Astrophys. in press, (1997). "Coronal Heating and the Vertical Temperature Structure of the Quiet Corona", M. S. Wheatland, P. A. Sturrock, and L. W. Acton, submitted to Astrophys. J. in press, (1997). "Nitric Oxide Abundance in the Mesosphere/Lower Thermosphere Region: Roles of Solar Soft X Rays, Suprathermal N(4S) Atoms, and Vertical Transport" by P. K. Swaminathan, D. F. Strobel, D. G. Kupperman, C. Krishna Kumar, L. Acton, R. DeMajistre, J.-H. Yee, L. Paxton, D. E. Anderson, and D. J. Strickland, submitted to JGR (Atmospheres). OUTREACH and SERVICE: An alpha version of the "Solar Tour" product for the Yohkoh Public Outreach Project (YPOP) was produced by Tim Slater with the help of Michelle Larson and David McKenzie for review by the YPOP team. This is a really nice educational tool. Acton, Canfield and Weston made good progress on organizational matters for the AAS Solar Physics Division meeting -- to be held at MSU 27 June - 1 July 1997. Meeting information and registration and abstract forms may be found at http://solar.physics.montana.edu/SPD/. Canfield and Pevtsov completed their proposal to the AGU for a Chapman Conference on Magnetic Helicity planned to be held at HAO in Boulder. In early November Acton gave assemblies at 3 middle schools in Great Falls, MT, a middle school and elementary school in Choteau, MT, and an elementary school in Bozeman. VISITORS: We greatly enjoyed a seminar and colloquium by B. C. Low near the end of January. Low's increasingly detailed description of how the solar cycle operates in the sun's corona stimulated animated discussions. TRAVEL: During the bimester both Canfield and Weber served tours of Yohkoh operational duty in Japan. Acton made a brief visit to Palo Alto on Yohkoh and YPOP affairs. Page 10 ======================================================================= Univ of Calif, Berkeley Activity Report for December 1996-January 1997 ======================================================================= (J. McTiernan) J.McTiernan attended the HXT Image Reconstruction Workshop, which took place at Lockheed, during 13-jan-1997 to 16-jan-1997, taking part in the HXT image synthesis group. McTiernan collaborated with T. Metcalf, and J.Sato to incorporate Sato-san's new HXT-LO and M1 modulation patterns into the program HXT_MULTIMG. These changes are now online at ISAS, to invoke the new patterns, set the /sato_patterns keyword in HXT_MULTIMG. These are still preliminary calculations; further improvements will come online as they are incorporated. Page 11 ============================================================= Univ of Hawaii Activity Report for December 1996-January 1997 ============================================================= (B. LaBonte) MAJOR ACTIVITIES FOR DECEMBER THROUGH JANUARY 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 Nitta at Mees, by Jiao, and LaBonte in Manoa. Our colleagues Mickey at Manoa, 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. The POI instrument has been returned to operation with the installation of the backup camera. Repair of the Stokes polarimeter is nearly completed. An intermittent problem with the MCCD shutter has been identified as a problem in the feedback loop and a resolution is underway. Weather was poor in December but much better and more stable pattern arrived in January. LaBonte continued work with Hudson on the isolated active region AR7978. During its second disk passage as AR7981, the decay of sunspots and magnetic complexity was accompanied by an increase in the flare rate and flare sizes. The effects of this region in energizing an entire hemisphere of the corona are dramatically seen in the SXT images for the July 1996 time period. A presentation of the early phase of the study of this region was made at the Fall American Geophysical Union meeting. In Dec, 1996, Litao Jiao continued his work on three dimensional reconstruction of solar coronal magnetic field based on Mees Stokes Data at SDSC. On studying some of the computational result (3-dim) graphically, they found the ambiguity resolution of the magnetogram sometimes plays an important role in leading to the stable state. The ambiguity correction method relies to some extent on comparing the measurements with the computed potential field or linear force-free field, which is not good in case the fluxes do not balance within the magnetogram field of view. Currently, he is testing on how to improve the stability of the method. When applying methods such as embedding Mees Stokes vector magnetogram into Kitt Peak LOS magnetogram to balance flux, some spurious currents will be introduced around the edges of the intersection. Such problems are need to be investigated. January 1997 was Jiao's last month in YOHKOH project. He will voluntarily continue to serve in rotation to be YOHKOH Duty Scientist until end of 1997. Jan. 1997 was an busy but very fruitful month, Dr. Sandy McClymont has greatly explored their research dimension, worked with him, Jiao has gained a lot of Page 12 experience and ideas on how to throughly explore the comparison of their computational results and SXT data. Dr. Sandy McClymont and Jiao submitted a proposal to the San Diego Supercomputer Center by the end of January. PUBLICATIONS AND PRESENTATIONS DURING DECEMBER AND JANUARY Papers Published: "The Imaging Vector Magnetograph At Haleakala", D. L. Mickey, R. C. Canfield, B. J. LaBonte, K. D. Leka, M. F. Waterson, and H. M. Weber, Solar Physics 168, 229 (1996). Papers submitted: "Problems & Progress in Coronal Three-Dimensional Coronal Active Region Magnetic Fields from Boundary Data", by McClymont, A. N., Jiao, L. (U. Hawaii), & Mikic, Z., Ap. J. "Reconstruction of the Three-Dimensional Coronal Magnetic Field", by Jiao, L., McClymont, A. N., Canfield, R. C., and, Mikic, Z., Solar Physics. "X-ray Photon Spectroscopy with the Yohkoh Soft X-ray Telescope", B. LaBonte and K. Reardon, Solar Physics. Presentations given: "The Isolated Solar Active Region NOAA AR7978", B. LaBonte (U. Hawaii), H. S. Hudson (SPRC), and T. Watanabe (NAOJ), American Geophysical Union Fall Meeting, December 1996. Page 13 ============================================================ Stanford Univ Activity Report for December 1996-January 1997 ============================================================ (M. Wheatland) Mike Wheatland began work during the reporting period on developing a novel variational method (by George Roumeliotis) for reconstructing force free-fields in the solar corona. George previously produced a working 2-d code which gave promising results in reconstructing simulated fields. Mike will produce the full 3-d implementation, written in the C programming language. A first step has been the production of a successful (and useful) potential field code. Our new Post-Doctoral fellow, Clare Parnell, worked during the reporting period on a simple model for compressive heating which may be appropriate to solar flares, and gives a possible explanation for some of the bright soft X-ray features observed by Yohkoh. The model presupposes that a piston, produced by the effect of magnetic tension in just-reconnected field lines, drives a shock in a magnetic flux tube in the solar atmosphere. Initial calculations suggest that the flux tube is efficiently heated by the passage of the shock for reasonable model parameters. A more detailed model is now being formulated. Peter Sturrock and Mike Wheatland have been collaborating with Guenther Walther of the Statistics Department in analyzing solar neutrino data in comparison with solar activity data such as sunspot number. The goal is to try to determine whether any aspect of solar activity is driven by processes deep in the solar interior (below the convection zone). Walther has produced a strong argument that the neutrino flux is not stationary. We are also finding some evidence that the neutrino flux exhibits the quasi-biennial periodicity (about 780 days) and some evidence that it exhibits the Rieger periodicity (of 150 - 156 days). If this evidence holds up, it will be interesting to examine Yohkoh data to see if the coronal X-ray emission is modulated at either of these periodicities. Clare Parnell has also been responsible for increasing the level of interaction between the Stanford group and the solar group at Lockheed. Two joint meetings of the groups were held during the reporting period. Papers accepted: Wheatland, Sturrock and Acton, "Coronal Heating and the Vertical Temperature Structure of the Quiet Corona," accepted for publication in the Astrophysical Journal (482, June 1997) Page 14 =========================================================================== Solar Physics Research Corp. Activity Report for December 1996-January 1997 =========================================================================== (Karen L. Harvey and Hugh S. Hudson) KAREN L. HARVEY: (1) Analysis of activity complex 7958/7979: Work is now proceeding with Debi Prasad and Harry Jones of the day-by-day history and magnetic field changes observed in the NSO photospheric and chromospheric magnetograms and HeI spectroheliograms. The detailed comparison of the coronal fields is being done with Hugh Hudson to trace the time history of the connections that develop and change with the emergence of magnetic fields and and the dispersal of the active region remnant fields. The history of this complex is being traced from its first emerged in late April 1996 to its January 1996 disk passage. The results of an initial examination of the evolution of the fields in the activity complex 7958/7978 is being written for the proceedings of the Yoyogi meeting held in early November. Two additional papers are planned, one describing the evolution of the magnetic fields and one dealing with the evolution of the X-ray coronal structures and their comparison with the magnetic field development. (2) Continued development and refinement IDL program to draw the irregular coronal hole boundaries on the NSO/KP He I 10830 spectroheliograms. The program is being adapted for the NSO/KP Carrington rotation He I 10830 maps. Application of this program will be used to define the boundaries of coronal holes (latitudes and longitudes) in Carrington rotations 1892 to 1984 for a paper coming out of the Bern Workshop on Coronal Holes. Lead author M. Neugebauer, co-authors: Z. Mikic, J.-M. Wang, A. Lazarus, R. Forsyth, Lepping, R. Wimmer, A. Galvin, R. von Steiger, K. Harvey. (3) Analysis of observations of XBPs obtained though a collaboration of several ground-based observatories and the Yohkoh SXT instrument, and SOHO in early April and late May 1996: Work is concentrated on the 12 April 1996 data and comparisons of the HeI 10830 line depth, magnetograms, and the series of EIT images made in He II 304, Fe XII 195, Fe 171 Initial results will be included in a paper on EIT/SOHO first results written by D. Moses. (4) Continued analysis of the collaborative observations of XBPs obtained in the several XBP campaigns between Yohkoh/SXT, NSO/KP, MSO, BBSO, HAO, SOONSPOT. (5) Preparation of NSO/KP full-disk magnetograms and He I 10830 spectromagnetograms for SXT investigators for studies of the magnetic field and He I 10830 structures associated with X-ray structures. Activities for February and March are to continue the refinement of the coronal hole boundary routines and implementing these routines using the NSO/KP data initially targeting specific periods, e.g. 1995 and 1996. Page 15 The analysis of the data acquired during XBP campaigns will continue. We expect to complete of the analysis of the history of the activity complex 7958/7978 and produce drafts of the next two papers planned on this work. HUGH HUDSON: H. Hudson continued to work on X-ray counterparts of CMEs, especially concentrating on the dimming signature. This has involved a substantial amount of planning for a Coordinated Data Analysis Workshop, the first of a SOHO/Yohkoh series, to take place at GSFC in March (on the subject of CMEs). At the time of writing the event list for this CDAW consists of 25 Sep 1996, 5 Oct 1996, 30 Nov 1996, and 6 Jan 1997. Note how productive the Sun is in this department during solar minimum! In all of these we have interesting overlapping data, with perhaps the most interesting being the almost total lack of X-ray signatures during the 6 Jan. 1997 "halo CME" event, which has stirred up considerable interest. In other areas, Hudson participated in the hard X-ray imaging workshop in Palo Alto in January and was duly impressed by the substantial improvements in calibration databases and software for working with the HXT data. Congratulations are in order for the HXT data analyzers. He also served as SXT chief observer around the New Year's holiday break and did normal operations support work. PLANS FOR FEBRUARY AND MARCH Research work in February will concentrate on preparations for the CDAW in March. This means continued work on CME counterparts, especially the four listed above. During this time a journal article including SXT data on the remarkable 5 Oct 1996 event (one of the prime CDAW events) should really be drafted - this event resembles the 28 Aug 1992 event (but seen at a much higher altitude) in terms of the filamentary bright loop structures in the ejection. However in this case SXT sees them apparently in the process of interaction, so that empirical reconnection rates can be crudely estimated. In March Hudson intends to visit D. Melrose in Sydney, and this will be an opportunity to think more deeply about the Masuda event and the general status of the non-thermal electron problem in solar flares. Although it's an extrapolation, we feel that this problem also exists for CMEs, since even "slow LDEs" show hard X-ray emission in the BATSE data, for example. The technical advances displayed at the Palo Alto CDAW show that the initial interpretation of the hard X-ray emission (by Masuda et al.) needs substantial revision, and this probably will affect the theoretical work that has been done by Wheatland and Melrose and by Fletcher. Papers published Page 16 H.S. Hudson, J.R. Lemen, and D.F. Webb, Coronal dimming in two limb flares, in R.D. Bentley and J.T. Mariska (eds)., Magnetic Reconnection in the Solar Atmosphere, ASP Conf. Proc. 111, 379-382, 1996. Z. Svestka, F. Farnik, H.S. Hudson, Y. Uchida, and P. Hick, Large-scale active coronal phenomena in Yohkoh SXT images, in R.D. Bentley and J.T. Mariska (eds)., Magnetic Reconnection in the Solar Atmosphere, ASP Conf. Proc. 111, 388-392, 1996. D. Alexander, T. Metcalf, and H.S. Hudson, Pixon reconstruction and the Masuda event of 1992 Jan. 13, in R.D. Bentley and J.T. Mariska (eds)., Magnetic Reconnection in the Solar Atmosphere, ASP Conf. Proc. 111, 253-256, 1996. A.C. Sterling, H.S. Hudson, and J.R. Lemen, Yohkoh BCS observations of the "reconnection region" of a solar flare, in R.D. Bentley and J.T. Mariska (eds)., Magnetic Reconnection in the Solar Atmosphere, ASP Conf. Proc. 111, 177-182, 1996. J.I. Khan, H.S. Hudson, A.C. Sterling, and J.R. Lemen, A loop flare observed by Yohkoh on 1992 July 11, in R.D. Bentley and J.T. Mariska (eds)., Magnetic Reconnection in the Solar Atmosphere, ASP Conf. Proc. 111, 162-165, 1996. H.S. Hudson and J.I. Khan, Observational problems for flare models based on large-scale reconnection, in R.D. Bentley and J.T. Mariska (eds)., Magnetic Reconnection in the Solar Atmosphere, ASP Conf. Proc. 111, 135-144, 1996. M. Takahashi, T. Watanabe, J. Sakai, T. Sakao, T. Kosugi, T. Sakurai, S. Enome, H.S. Hudson, S. Hashimoto, and N. Nitta, Publ. Ast. Soc. Japan 48, 857, 1996. F. Farnik, Z. Svestka, H.S. Hudson, and Y. Uchida, Large-scale active coronal phenomena in Yohkoh SXT images, II, Solar Phys. 168, 331, 1996. Page 17 ------------------------------------------------------------------------------- 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 February 1997 January 1997 |------------------------------- | 6. PERFORMING ORG | CODE: O/H1-12 -----------------------------------------------|------------------------------- 7. AUTHOR(S) | 8. PERFORMING ORGANIZA- J. R. Lemen | TION REPORT NO: F. M. Friedlaender | |------------------------------- -----------------------------------------------|10. WORK UNIT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS | Lockheed Palo Alto Research Labs B/252 |------------------------------- Solar & Astrophysics Laboratory O/H1-12 |11. CONTRACT OR GRANT NO. 3251 Hanover Street, Palo Alto Ca. 94304 | NAS8 - 40801 -----------------------------------------------|------------------------------- 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 | of January 1997 |------------------------------- |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 | 17 | ------------------------|------------------------|-----------------|----------- For sale by: Superintendent of Documents, U.S. Government Printing Office