Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-00119) (for July 2000) 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 new contract is well underway and the transition was seamless.The instrument continues to operate well and some personnel changes are contemplated that will make the operations at ISAS more efficient. SOLAR ACTIVITY In early July, activity increased to mid-C levels without resulting in major flares. Simnett might claim that there are too many active regions, and the corona won't allow flare build-up. In mid-July, activity settled in at the mid- to high-C level with numerous M-class flares and a couple of X-class flares, including the largest flare in 6+ years from AR #9077 (X 5.7). Pat McIntosh labeled this the "Super Active Region" just as it came over the limb, and his predictions held true. NOAA 9077 attained a sunspot area exceeding 1000 millionths on July 11, with a delta configuration, and duly produced X-class flares on July 11, 12, and 14. The event on the 14th (Bastille Day again) was exceptionally well-observed both by Yohkoh and TRACE and was the largest yet of this cycle. We have now had 11 X-class flares this year. Also, of course, an appropriate number of M-class flares, more than thirty during these two weeks. On July 21, just for illustration, NOAA listed 17 active regions and a total of 231 individual spots. The flare trigger level remained at at 2x normal during this interval, in order not to have continuous triggering. In late July, activity ceased pretty completely, though there were seven Page 2 M-class flares towards the beginning of the interval. CAMPAIGNS In early July, there were no organized campaigns, but we were pleased enormously to see that the X-class flare of July 14 was well-observed both by Yohkoh and by TRACE. Yohkoh co-observed with the SERTS rocket flight along with CDS and VLA whose observations were also oriented to DEM studies. The rocket went off OK and probably observed the end of a C-class flare; Yohkoh did not get exactly simultaneous data and suffered from some saturation in the SXT images because of the flare. SCIENCE Acton continued to analyze SSC (SXT Science Composite) and the derivative SXH (SXT X-ray Histogram) files for quality and validity. While there are still some problems with these data they will clearly be a great improvement over the old SFDs for quantitative work. Nitta studied the relation between eruptive flares and CMEs. He looked at TRACE images for low coronal signatures of CMEs that originated from disk regions. Although (like pre-flare activity) changes in a filament or loop expansions are seen 5-30 minutes before the flare onset, the real eruptions appear to start with the impulsive phase, around the time of X-ray ejections as seen in SXT images. So in these events, the usual statement that a flare is just an aftermath of a CME does not hold. The cusp configuration in soft X-rays - also known as a "helmet streamer" - has a very direct significance to people studying the solar corona. Normally its pointy geometry means oppositely directed magnetic fields, a thin current layer to keep them apart, and... MAGNETIC RECONNECTION because the fields have the right orientations to do that. The physics of magnetic reconnection is incalculably important in understanding the behavior of the solar corona, since, in the concentric region between the photosphere and the solar wind, the field dominates the forces at work. It is much stronger than gravity or gas pressure, as a rule. Thus we keep our eyes peeled for beautiful cusps, such as the one accidentally caught just as the Moon was crossing the face of the Sun in a partial eclipse of Feb. 16, 1999. The interesting thing was the occurrence of not one, but two successive cusp features in the same active region. Unlike the case of the imperturbable cusp reported in a science nugget from last month, in this case the cusp created by one flare was grossly perturbed (perhaps destroyed) by a flare the very next day. Here then is a case where the flare, an M7 event, seems to have disrupted an adjacent part of the coronal magnetic field - a "restructuring". Both of these cusps, as is common, followed major flares of the type associated with CMEs - we can't check their occurrence directly this Page 3 time, though, because the LASCO coronagraphs on SOHO were in the middle of a short break in observations with mirror doors closed to avoid contamination during a thruster firing. PUBLICATIONS Submitted: Wheatland, M.S., Sturrock, P.A., & Roumeliotis, G. 1999, An Op- timization Approach to Reconstructing Force-free Fields, ApJ, submitted. Accepted: Nature of Solar Polar Rays 2000. Li, J., Jewitt, D., LaBonte, B. J. Astrophys. J. Lett., August 10. "Non-coronagraphic Observations of CMEs", H. S. Hudson and E. W. Cliver (JGR) 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., and Weber, M. 1999, Coronal X-ray Brightness and Photospheric Magnetic Field: A Study in Correlations, ApJ, in press. Published: Global Solar Corona Revealed by Time Series Observations 2000. Jing Li, Jeff Kuhn, Barry LaBonte, John Raymond, Loren Acton, Astrophys. J., 538, 415. "On the Nature of the "Moss" Observed by TRACE", P.C.H. Martens, C.C. Kankelborg, and T.E. Berger 2000, Astrophys. J., 537, 471-480. "Highly Energetic Physical Processes and Mechanisms for Emissions from Astrophysical Plasmas", Proceedings of IAU Colloquium 195, P.C.H. Martens, S. Tsuruta, and M.A. Weber (eds.), PASP 2000, has come off the press and has been mailed to the participants. Roald, C.B., Sturrock, P.A., Wolfson, R. 2000, Coronal Heating: Energy Release Associated with Chromospheric Magnetic Reconnec- tion, ApJ, 538, 960. 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 Page 4 day. The WEB access statistics in July were 130617 accesses and 7184 Mbytes transferred for the SXT website and 148163 accesses and 3522 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: Bit Map Error 06-Jul-00 Pass 1: 000706-1445 Recovered in the same pass Page 5 DATA FLOW Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Thru May-98 545845 206311 2203296 471742 2675038 990392 26.76 Jun-98 6463 1638 24990 5618 30608 9051 22.82 Jul-98 6810 1892 27046 7357 34403 9970 22.47 Aug-98 5823 1960 22978 14126 37104 11167 23.13 Sep-98 6776 1432 21814 11626 33440 7753 18.82 Oct-98 6573 1901 23520 5198 28718 9220 24.30 Nov-98 6442 1695 25124 26948 52072 9920 16.00 Dec-98 5962 2005 21490 15770 37260 10561 22.08 Jan-99 5494 1825 20087 17620 37707 9622 20.33 Feb-99 5729 1525 30802 9798 40600 10630 20.75 Mar-99 6807 1844 24721 12354 37075 10064 21.35 Apr-99 6715 1371 25113 4179 29292 7791 21.01 May-99 6459 1807 35467 12092 47559 13757 22.44 Jun-99 6217 1915 23542 13051 36593 10086 21.61 Jul-99 5591 1745 20409 25747 46156 9670 17.32 Aug-99 6827 2503 21725 23361 45086 11844 20.80 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 4799 1121 16697 28056 44753 6285 12.31 Total 710764 256198 2824584 814205 3638789 1253010 25.61 Number of Full Frame Images Received: 710764 Number of Observing Region Images Received: 3638789 Total: 4349553 Approximate Number of Shutter Moves/CCD Readouts: 7378719 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 (%) Jun-98 57.11 997.5 216285 28223 20.1 N/A Jul-98 57.01 993.7 215499 27493 21.4 N/A Aug-98 57.36 1006.7 217355 29544 20.9 N/A Sep-98 57.43 1009.5 218520 29683 20.9 N/A Oct-98 57.59 1015.3 220504 30221 21.3 N/A Nov-98 58.17 1037.0 223755 34614 22.5 / 2 23.4 N/A Dec-98 57.86 1025.5 221918 32420 23.8 N/A Jan-99 58.74 1058.6 227503 38238 23.1 N/A Feb-99 58.44 1047.4 224002 36198 23.2 N/A Mar-99 59.26 1078.1 227900 43051 21.7 N/A Apr-99 58.82 1061.4 225973 38963 23.8 / 1 21.4 N/A May-99 58.68 1056.4 225385 37726 21.6 N/A Jun-99 59.40 1083.0 230091 42440 22.0 N/A Jul-99 59.78 1097.5 231236 46337 23.8 / 1 20.6 N/A Aug-99 59.39 1083.0 229319 43067 21.7 N/A 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 62.02 1181.4 238335 67501 17.8 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-JUL-00 and 31-JUL-00 HANDY 1-JUL-00 * 20-JUL-00 20 (total of 20 days) HUDSON 1-JUL-00 * 11-JUL-00 11 17-JUL-00 31-JUL-00 * 15 (total of 26 days) ---------------------------------------------------------------- Grand Total of 46 days for 2 people NOTE: The "*" signifies travel that actually ends after 31-JUL-00 SXT Foreign Travel between 1-AUG-00 and 31-AUG-00 FLETCHER 4-AUG-00 31-AUG-00 * 28 (total of 28 days) HUDSON 1-AUG-00 * 31-AUG-00 * 31 (total of 31 days) ---------------------------------------------------------------- Grand Total of 59 days for 2 people NOTE: The "*" signifies travel that actually ends after 31-AUG-00 Respectfully submitted, Thomas R. Metcalf Frank Friedlaender Page 8 7 ================================================================= Montana State Univ Activity Report for June 2000-July 2000 ================================================================= (A. Davey) Conferences ----------- During June Acton attended the AURA Solar Observatory Council in Tucson and the AAS meeting in Rochester, where he gave Hale Prize lecture. He also attended a meeting on ITAR (Int'l Traffic in Arms Regulation) in Washington as Sen. Burns' representative. A number of MSU solar physicists, Acton, Canfield, Handy, Kankelborg, Martens, Mckenzie attended the SPD meeting at Lake Tahoe, presenting various talks and posters. Science ------- During June Acton worked with Jing Li on an SXT analysis problem; the effect of vignette correction on total x-ray irradiance. For the disk (r<0.85) the corrected irradiance is about 10% higher. For r>1.05 the increase is more like 30%. Overall, the correction amounts to about 25%. The day analyzed was 19-Dec-97. Acton concluded that vignette correction should be included in production of SXH (histogram files prepared from SSC (SXT Science Composite)) files and published irradiances. Acton also performed a reanalysis of the effects of sxt_xsaa.pro on removal of SAA streaks in SSCs. He concluded that the present code is OK for cleaning up show movies but should not be used on images intended for quantitative analysis. Some small genuine x-ray features are effected, although seldom by more than 10%. During June, with Zarro and Demoulin, Canfield worked on a poster paper for the SPD meeting in which co-aligned SXT, TRACE, SoHO, BSO, and SOON movies and Mees vector magnetograms for flares observed in the sigmoidal active region AR 8668 during Whole Sun Month 3, were compared to the topological model of Titov and Demoulin (1999). The comparison shows many similarities between the observations and predictions of the model. Canfield continued work with Jibben and Pevtsov on the comparison of SXT jet / MCCD surge events to maps of twist in photospheric magnetic fields inferred from Mees vector magnetograms. Canfield and Bambeck developed software for stepping region by region through SXT images in a highly automated manner. Burnettte finished a comparison of force-free field parameters derived from SXT images to those derived from Mees vector magnetograms, and started writing a paper with Canfield and Pevtsov. High school students Kendall Harwood and Shanara Spang, participants in the American Indian Research Opportunities (AIRO) Montana Apprentice Page 9 Program, started producing CD-Rs of the Mees H-alpha coronagraph data to support the study by Tonooka san and Canfield of eruptive events seen in both H-alpha and SXT images. During July, Acton further assisted Jing Li with a poster for the Manchester IAU entitled, "Solar Polar Rays are Not Polar" by Jing Li, David Jewitt, Barry LaBonte, and Loren Acton. This is the first use of the SXT SSC floating point composite images for research. He continues to analyze SSC (SXT Science Composite) and the derivative SXH (SXT X-ray Histogram) files for quality and validity. While there are still some problems with these data they will clearly be a great improvement over the old SFDs for quantitative work. Canfield continue working with Jibben and Pevtsov through July on the work described previously. He worked with Bambeck and Longcope on software for objective recognition of sigmoids in SXT sfd images. He worked with McMullen to determine tilt per unit length of specific NOAA ARs from Mt Wilson data furnished by Bob Howard. He also continued work with high school students Kendall Harwood and Shanara Spang. In July, during his stint as Chief Observer Handy, updated the SFD movie on Laserdisk to week 00_25, and assisted with various system activities, working notably to expand the available TRACE data at ISAS. Handy also worked with R. Kano to improve the ability to independently predict solar eclipse transits. He also started collecting datasets from the X5.x flare of 14-July-2000 for future work with Hudson & Canfield. McKenzie with inspiration from Paulett Liewer's presentation at the Lake Tahoe SPD meeting, started a small project to compare the locations of spikey arcades with the heliospheric current sheet in a potential source surface model. Liewer et al. found that 8 out of 8 streamer stalks in LASCO could be traced to fall (nearly) exactly in the current sheet in the PSS. McKenzie thinks a similar comparison might be interesting for post-CME arcades, perhaps to yield a clue as to why some arcades are spikey and some aren't. On preliminary findings, it appears that spikey arcades are all over the map, with no obvious correlation to the current sheet. McKenzie also examined SXT images from the X-class flares of 11-jul, 12-jul, and 14-jul, in order to judge the recent adjustments to the automatic exposure control (AEC) parameters. Late in 1999, the AEC thresholds were tweaked to allow intensity-specific deep exposures in the half- and quarter-resolution flare mode images; prior to the adjustment, these exposures were of a fixed duration. In the three X flares above, it is believed the AEC response was appropriate. During July, Martens worked with Paul Wood, an undergraduate from St. Andrews visiting here for the summer, on putting together observations of three neat filaments observed in recent years, see: http://solar.physics.montana.edu/wood/ Martens also worked with Ryan McWilliams, a high school student, and summer intern, on putting together an MSU solar physics gallery -- to be opened next month. Outreach and Service Page 10 -------------------- In June, Acton gave 3 talks to groups of high school students visiting MSU under different summer programs. During June and July, Canfield reformatted the SXT Chief Observer's weekly reports at http://solar.physics.montana.edu/nuggets/ and mirror sites at Lockheed, ISAS, and MSSL. He set up a talk series for the MSU REU students and performed refereeing duties. Following discussion with Hugh Hudson regarding the Magnetic Reconnection-2000 proceedings article on "slow LDEs". McKenzie prepared a press release regarding the "reconnection outflow" interpretation of the supra-arcade downflows, in preparation for the SPD meeting. The story was picked up by the New York Times, San Francisco Examiner, Space.com, and the Bozeman Daily Chronicle. During July, Acton gave a talk at the asthma camp of the Am. Lung Assoc. and attended an AURA Solar Observatory Council tele-meeting. Canfield gave a talk on "Solar Space Research" to the Upward Bound Math and Science program, MSU Bozeman, July 25, 2000. Mckenzie provided some info about solar flares, CMEs, and reconnection to "The Why Files", a web-based feature magazine. That article appeared on http://whyfiles.news.wisc.edu/ on July 28. Publications ------------ "On the Nature of the "Moss" Observed by TRACE", P.C.H. Martens, C.C. Kankelborg, and T.E. Berger 2000, Astrophys. J., 537, 471-480. "Highly Energetic Physical Processes and Mechanisms for Emissions from Astrophysical Plasmas", Proceedings of IAU Colloquium 195, P.C.H. Martens, S. Tsuruta, and M.A. Weber (eds.), PASP 2000, has come off the press and has been mailed to the participants. Talks Given ----------- Zarro D.M., Canfield, R.C., Demoulin, P., Nitta, N., Myers, D.C., Gregory, S.E., Qiu, J., Alexander, D., Hudson, H.S. Thompson, B.J., LaBonte, B.J., "Max Millennium/Whole Sun Month Observations of a Sigmoid Region (AR 8668)", Solar Physics Division meeting, Lake Tahoe (2000). Harwood, K., Spang, S., Canfield, R. C., Jibben, T., Kintzing, D. "Studying Eruptions on the Sun", Montana High School Research Apprenticeship Program, American Indian Research Opportunities Symposium, MSU Bozeman, July 20, 2000. Page 11 Operations ---------- During June, Canfield served one week as Yohkoh Duty Scientist at Mees Solar Observatory. Handy went to Japan on 14-June-2000 for SXT Operations, where he stayed doing Chief Observer work until July 21. ============================================================= Univ of Hawaii Activity Report for June 2000-July 2000 ============================================================= (B. LaBonte) 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 and LaBonte and Li in Manoa. Our colleagues Kupke and 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. Weather at Mees was fair, with typical summer conditions of daytime cloud buildup. However, some observations were obtained on 89% of all scheduled days. The best observed flare-productive region was AR9026 in June, which produced several X flares; during Mees hours we captured an M7.6 event on June 2. LaBonte is continuing work on the mapping of electric currents in several active regions, including the Whole Sun Month region of August 1999 and the flare productive region AR8210 of May-June 1998. LaBonte has begun work on a collaborative analysis of observations from Mees, YOHKOH/SXT, and a variety of other sources in concert with the Flare Genesis mission in January 2000. H-alpha imaging spectra and IVM movies were obtained on several days with good Flare Genesis coverage at high spatial resolution. Li is working with G. Slater (LMSAL) to extend her mapping of coronal streamers to the full Yohkoh/SXT dataset, covering nearly an entire solar cycle. The SXT data processed thus far show streamer and global coronal structure much more clearly than the SOHO/EIT data, because of the absence of transition region emission. Mickey, in collaboration with T. Metcalf and L. Fletcher (LMSAL) has made progress on analysis IVM observations from the Max Millennium Page 12 Observing Plan 006 campaign to search for impact polarization in H-alpha during the impulsive phase of flares. Various theoretical predictions permit a wide range of polarization. Preliminary analysis of 2 days from the 3 week campaign show no detectable signal at the level of a few percent, but the limit is still set by incomplete compensation for time variation in the seeing. The extreme contrast of the flare makes this problem much more difficult than the normal correction of the photospheric magnetograms. These results are similar to those found by Fisher's group (UC Berkeley). PRESENTATIONS AT MEETINGS: Solar Physics Division Meeting, Tahoe, June 2000 Electric Current Systems in Solar Active Regions 2000. LaBonte, B. J., and Mickey, D. L. BAAS, 32, 809. Physical Properties of Solar Inner Corona Revealed by Time Series Observations Made by EIT and SXT 2000. Li, J., LaBonte, B. J., Acton, L. W. BAAS, 32, 815. Evolution of the Solar Corona From Cycle 22 to Cycle 23 as Revealed by X-ray Limb Synoptic Maps 2000. Slater, G.L., Freeland, S. L., LaBonte, B. J., Li, J., Acton, L. W. BAAS, 32, 815. Max Millennium / Whole Sun Month Observations of a Sigmoid Region (AR 8668) 2000. Zarro, D. M., Canfield, R. C., Nitta, N., Myers, D. C., Gregory, S. E., Qiu, J., Alexander, D., Hudson, H. S., Thompson, B. J., LaBonte, B. J. BAAS 32, 817. Observations of H-alpha Polarization in Flares. 2000. Mickey, D. L., Metcalf, T. R., and Fletcher, L. BAAS, 32, 820. PAPERS ACCEPTED FOR PUBLICATION: Nature of Solar Polar Rays 2000. Li, J., Jewitt, D., LaBonte, B. J. Astrophys. J. Lett., August 10. PAPERS PUBLISHED: Global Solar Corona Revealed by Time Series Observations 2000. Jing Li, Jeff Kuhn, Barry LaBonte, John Raymond, Loren Acton, Astrophys. J., 538, 415. Page 13 =========================================================================== Solar Physics Research Corp. Activity Report for June 2000-July 2000 =========================================================================== (Karen L. Harvey and Hugh S. Hudson) KAREN L. HARVEY: Activities for June and July: (1) Continued analysis of data on project with Terry Forbes to determine as a function of time the magnetic flux bounded by He I 10830 the two flare ribbons and in the transient coronal holes associated with these flares . Much of the work to date is being devoted to writing the software to outline the structures in the HAO/CHIP He I 10830 images and to accurately locate these outlines on the corresponding NSO/KP, but single, full-disk magnetogram. We are testing these programs on one event observed on 18 December 1998. Once finalized, additional days will be examined. In addition, we are comparing the He I 10830 results (i.e. the locations of the flare ribbons and transient holes) to the SXT images for this (and eventually other) event to determine specifically in detail how the transient coronal holes compare spatially and temporally with X-ray dimming events. The objective of this study is to determine the reconnection rate of the flare. Two measurements will be made with time using a singe NSO/KP full-disk magnetogram (this assumes that the photospheric field does not change over the observed life of the flare): the magnetic flux within and bounded by the flare ribbons, and the magnetic flux within the transient holes. (2) Continued 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 and the relation between the mean He I 10830 equivalent width and X-ray emission summed within the hole boundary. We are also investigating what new connections take place as the magnetic fields of emerging and dispersing active regions evolve leading eventually to the formation of isolated, non-polar holes. (3) Preparation of NSO/KP full-disk magnetograms and He I 10830 spectro- heliograms for SXT investigators for studies of the magnetic field and He I 10830 structures associated with X-ray structures. (4) Updating of the Yohkoh/SXT publication list. Plans for August and September Continued analysis and study of (1) the association of coronal holes observed in He I 10830 spectroheliograms and the SXT full-frame images; (2) a study with T. Forbes of the reconnection rate of magnetic fields Page 14 during long-duration arcade events/He I 10830 2-ribbon flares associated with X-ray dimming and transient coronal holes; (3) the XBP data collected during several observing campaigns, concentrating on the more recent runs, to derive the height and temporal structure of coronal and chromospheric bright points associated with magnetic flux cancellation and emergence; (4) updating the SXT publications list for refereed journals. HUGH S. HUDSON Activities for June and July: I didn't finish the May 6 wave paper, but thanks to Joe Khan it's just becoming more and more interesting. For example, it's now a May 6, 8, and 9 wave paper. In a sense SXT really sees waves as well as one could expect, and probably the main limitation in detection is the effect of high contrast and variable scattered-light contributions. The presentation at the SPD in Tahoe successfully (I think) introduced many people to the concept of "helioexalepidoptery". Some informal work has been done on the July 14 X-class flare, for which Brian Handy and I did a science nugget. There are many interesting aspects to this event, which was quite well observed by both Yohkoh and TRACE. This flare is now widely suspected of having caused the premature death of the ASCA satellite via a complicated mechanism involving atmospheric heating and a "safe-hold" mode that was not so safe. At present ASCA is not gone completely but apparently looks unrecoverable. Plans for August and September 1. Continue to work on the July 14 flare, emphasizing temperatures, HXT, and magnetic morphology. The idea of the latter, which Brian and I started to work on, is to make a detailed comparison of the footpoint morphology (extremely well defined by TRACE data) with the photospheric magnetic field. In earlier flares there have been hints that the "spreading moss" resulting from the arcade may not match the network pattern - if true, this would cry out for a fancy explanation. 2. Complete the jitter study - the remaining task is to do forward-method temperature mapping with the improved IRU data. 3. Work with recently acquired data from the "RAPID" image sequences, in which we get a DPE-21 exposure every 32 seconds during Yohkoh high rate, quiet mode. I'm convinced that these data will show us waves if only we look at them properly. Page 15 PUBLICATIONS: Papers Accepted "Non-coronagraphic Observations of CMEs", H. S. Hudson and E. W. Cliver (JGR) ============================================================ Stanford Univ Activity Report for June 1998-July 1998 ============================================================ (P. Sturrock) During the reporting period of June and July, 2000, the Sturrock Solar Research Group has continued to focus its efforts towards developing numerical models of coronal magnetic fields. These ef- forts have been devoted to modeling generic force-free fields ac- cording to a prescription set forth by Roumeliotis, and searching for an energetically metastable field configuration of a pre-CME flux tube. Mark Weber's main current activity has been to continue working on a project which investigates CME energetics, with a possible future extension to the applicability of the Aly-Sturrock theorem. It is hypothesized that a toroidal flux tube embedded in a dipole field might be metastable to eruption, i.e., the field contains more energy than the open-field solution yet is stable to small perturbations. This would correspond to the energy storage and structure which is conjectured to be necessary for CMEs. Mark hopes to numerically find a solution to the partial differential equations by relaxing an initial analytic approxima- tion suggested by Peter. The procedure is complicated by the presence of two distinct flux systems. During this reporting period, Mark has identified some of these complications and for- mulated solutions for them. The goal is to find the relaxed solu- tion and calculate the energy content of the field. Peter Sturrock also 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 has been exploring a generalization aimed at the construction of force-free fields that fall off as rapidly as possible with dis- tance. The generalization we are currently considering is to add to the optimization function a multiple of the square of the field strength, the coefficient being a function of position. Our idea was to choose the multiplying coefficient to be small in the interior of the field, and large at the outer boundaries. The convergence properties will probably depend both on the maximum value of that coefficient and the profile. For the case that Jim has already run, the program ceased to relax for a fairly small value of the coefficient. We hope that we will have better luck with different Page 16 profiles. Publications Roald, C.B., Sturrock, P.A., Wolfson, R. 2000, Coronal Heating: Energy Release Associated with Chromospheric Magnetic Reconnec- tion, 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 Op- timization Approach to Reconstructing Force-free Fields, ApJ, submitted. 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, in press. 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 August 2000 July 2000 |------------------------------- | 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 - 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 Contact: Larry Hill | of July 2000 |------------------------------- |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