*************************** ** THE GEM MESSENGER ** *************************** Volume 5, Number 19 September 7, 1995 ---------------------------------------------------------- Report on GEM Snowmass Meeting, June 26-30, 1995 - Part II ---------------------------------------------------------- BOUNDARY LAYER CAMPAIGN WG 1: RECONNECTION ELECTRIC FIELD AND MAGNETOPAUSE BOUNDARY NORMAL MAGNETIC FIELD Co-chairs: Larry Lyons and Nelson Maynard Below is a summary of accomplishments and plans on the various projects being pursued by this working group. PROJECT A: Identify separatrix and 2-dimensional flow versus time across and in vicinity of separatrix using data from periods of good multi-instrument coverage of the dayside cusp region at ~13 to 16 UT, with IMF available . 1. 29 Mar. 1992: Excellent Goose Bay coverage; variable IMF (IMF only available 1310-1930 UT) a. Goose Bay study of dayside reconnection rates including motion of polar cap boundary completed and paper being prepared (Baker). b. Relation of reconnection rates and boundary motions to good large-scale flow patterns obtained from AMIE (Lu) to be included in above paper c. Sondrestrom radar data available with cusp identifiable for two-point reconnection evaluation. Sondrestrom data analysis to begin in about 1 year (Blanchard) 2. 21 July 1992: Excellent Goose and Halley Bay data; well-defined IMF changes a. Reconnection analysis using simultaneous data from both hemispheres in progress; expect study to be completed by next year (Pinnock/Baker) b. Relation of reconnection rates and boundary motions to good large-scale flow patterns obtained from AMIE (Lu) to be included in above study c. Sondrestrom radar data available with cusp identifiable for two-point reconnection evaluation. Sondrestrom data analysis to begin in about 1 year (Blanchard) 3. 27 Jan. 1992: Period of relatively stable IMF a. Radar data not sufficient for general reconnection studies b. Interesting study possible for 16-1615 UT period when IMF By goes less positive, see rapid equatorward motion of separatrix at Halley Bay and Sondrestrom (Goose Bay?), and AMIE shows 4-cell convection pattern changing to two cell. No plans were formulated to pursue this study; however data can be made available to a volunteer. 4. Multi-event study of small-scale structure in reconnection rates to be pursued by Pinnock and Baker 5. Time-dependent analysis of cross-polar-cap potential drop and potential distribution along separatrix including comparisons with model predictions. Study should be completed and paper written in about one year (Hairston, Reiff, Lu). PROJECT B. Continued studies of Aug. 2-4 period 1. Definitive changes seen in large-scale AMIE potentials and currents in association with the Stauning et al. poleward progression events. Analysis complete and paper to be prepared (Lu). 2. Large shear seen is crescent-shaped convection cell on Aug.4 when Bz ~ 0 and |By| large. Observe ~30 min, 200-300 nT pulsations in Greenland B in region of strong shear that appears to result from a shear instability. Analysis is complete and paper is nearing completion (Clauer). PROJECT C: Identify and test separatrix identification techniques with dayside optical observations, DMSP, and radars. Dates: 6-7 Jan. 1992; 14 Jan. 1994, 6-7 Dec. 1994 1. Obtained general agreement of what feature in particle precipitation data identifies the separatrix near noon: The poleward boundary of the plasma sheet, which is collocated with the inner edge of weak fluxes of the low-energy electrons that are seen in the cusp. Note that boundary often is somewhat equatorward of the observed inner edge of cusp ion precipitation. Both cusp ion and electron boundaries are shifted poleward from the separatrix by poleward convection during the ion transit time. The gap size is related to the cross-boundary convection. Identification techniques: a. Direct particle observations on low-altitude satellite b. Radar: Looks for changes in the spectral characteristics of the echoes. Gives one-dimensional time history, and can potentially give two-dimensional structure as well as two-dimensional time history (Baker, Pinnock) c. Optical: new technique based on poleward boundary of plasma sheet as determined from 5577 A emissions now available; this boundary is located ~ 60 km equatorward of the low-latitude boundary of the cusp identified from 6300 A emissions. Technique works best when the cross-boundary convection is strong. A paper on this technique should be completed this summer (Minnow) 2. Planned test of techniques with existing data: a. Compare Halley radar, DMSP, and optical identifications from whatever data can be found (Pinnock, Mende) b. Use identifications with superDARN, with some results in ~1 year (Rodger) 3. Ideas are needed on how to extend separatrix identification away from noon towards dawn and dusk; as of now there is no general agreement on what feature is the separatrix. 4. Next winters Dec., Jan., Feb., and April campaigns: Use whole SuperDARN, Svalbard radar and optical, and other radars a. Test separatrix identifications b. Evaluate flows in vicinity of separatrix as function of IMF conditions c. Use WIND, POLAR, GEOTAIL, and Interball (on night side if launched successfully) data and work on night side and dayside together. PROJECT D: "Synoptic Space Weather Maps"; plots of whole polar cap including separatrix, boundary layers and AMIE potentials a. Two time periods during 27-29 Jan. 1992 so far available, paper to be completed before next year (Lyons, Lu, Rich) b. Are some important outstanding questions concerning separatrix identification c. Need to compare potential patterns and separatrix to models (e.g., Toffoletto-Hill and Schulz source-surface models) d. Need to do more cases; 12-13 Jan. 1989 and 20-21 July, 1992 to be considered LAST YEARS COMPLETED CAMPAIGNS: First SuperDARN reconnection studies a. 11-14 Jan. 94: 1 radar pair, plus Goose and Halley running b. 5-6 July 94: 1 radar pair, plus Goose and Halley running c. 5-7 Dec. 94: 2-pairs plus Halley running d. 28- Feb.- 2 Mar. 95: 2-pairs plus Finland and Halley running Look at radar data to determine when good data for separatrix identification and reconnection measurements is available (already know Halley data is excellent on 6 Dec.) __________________________________________________________ SUMMARY OF DATA CAMPAIGNS FOR BOUNDARY & TAIL/SUBSTORM CAMPAIGNS LAST YEARS COMPLETED CAMPAIGNS January 11 to January 14, 1994 * GEOTAIL in tail at ~ 90 Re (good data). * Good ground data from CANOPUS photometers, Svalbard photometers, world wide magnetometers, Sondrestrom radar * DMSP, GOES magnetometers, LANL geosynch. particles. * A number of good substorm events were seen whose analyses will continue at the GEM workshop. 10 UT July 5 to 18 UT July 6, 1994 * All radars, world-wide magnetometers, and CANOPUS photometers * IMP at (15,-29,19) to (29,-12,19); IMF coverage 04-19 UT on July 5, 0915-24 UT on July 6. 10 UT Dec. 5 to 18 UT Dec. 7, 1994 * All radars, world-wide magnetometers, and CANOPUS photometers, (Svalbard cloudy) * Wind at (50,-40,-2) GSE (100% coverage?) * GEOTAIL at (-40, -22,-6) to (-15,-25,-3)GSE (100% coverage?) * IMP at (23,17,-10) to (-4,35,11) GSE. Only 17 min gap planned, actual coverage 00-1130, 1230-2330 (Dec. 5); 13-2430 (Dec. 6); 1145-1730 (Dec. 7) 10 UT Feb. 28 to 18 UT Mar 2, 1995 * All radars, world-wide magnetometers, and CANOPUS photometers * IMP coverage begins 1205 UT on Feb. 28, all but 49 min of data recovered * WIND at ~(205,-6,11); GEOTAIL at (7,24,-3) to (-20,16,-3) PLANS FOR THIS FALL AND WINTER (SO FAR)(satellite positions approximate as they are based on early predicts) In conjunction with radar world days & gismos (IMP in solar wind) (large-scale data set development; occasionally used for event studies) 22-24 Aug. 1995: Three satellites in dawn-side solar wind! Time Sat. GSE (RE) GSM (RE) Spacecraft yyyy ddd hh:mm X Y Z X Y Z Region 1995 234 00:00 geotail -10.9 -12.0 -0.9 -10.9 -12.0 1.2 Plasma Sh 1995 234 12:00 geotail -4.0 -21.8 -2.5 -4.0 -20.0 9.1 N Msheath 1995 235 00:00 geotail 4.3 -26.0 -3.4 4.3 -26.2 1.2 Intpl Med 1995 235 12:00 geotail 11.9 -26.3 -3.8 11.9 -24.5 10.3 Intpl Med 1995 236 00:00 geotail 18.1 -23.6 -3.8 18.1 -23.9 0.5 Intpl Med 1995 236 12:00 geotail 22.1 -19.4 -3.4 22.1 -18.4 7.1 Intpl Med 1995 237 00:00 geotail 24.5 -12.5 -2.7 24.5 -12.8 -0.3 Intpl Med 1995 234 00:00 wind 25.4 -30.0 -1.2 25.4 -29.8 4.0 Intpl Med 1995 234 12:00 wind 33.3 -32.0 -1.7 33.3 -28.3 15.0 Intpl Med 1995 235 00:00 wind 40.4 -33.2 -2.1 40.4 -33.1 3.8 Intpl Med 1995 235 12:00 wind 46.8 -34.0 -2.6 46.8 -30.4 15.3 Intpl Med 1995 236 00:00 wind 53.1 -34.1 -3.3 53.1 -34.2 3.0 Intpl Med 1995 236 12:00 wind 59.0 -33.6 -4.0 59.0 -30.8 14.0 Intpl Med 1995 237 00:00 wind 64.3 -32.7 -4.8 64.3 -33.0 1.3 Intpl Med 1995 234 00:00 imp8 14.2 -32.0 16.3 14.2 -28.7 21.6 Intpl Med 1995 234 12:00 imp8 20.4 -28.9 12.4 20.4 -18.4 25.5 Intpl Med 1995 235 00:00 imp8 25.6 -24.2 7.8 25.6 -22.5 11.9 Intpl Med 1995 235 12:00 imp8 29.4 -18.2 2.7 29.4 -14.2 11.7 Intpl Med 1995 236 00:00 imp8 31.3 -11.0 -2.6 31.3 -11.3 -0.6 Intpl Med 1995 236 12:00 imp8 30.9 -3.0 -7.7 30.9 -6.6 -5.0 Intpl Med 1995 237 00:00 imp8 28.0 5.2 -12.1 28.0 2.9 -12.8 Intpl Med 21-22 Nov. 1995 22-24 Jan. 1996 (FAST collaboration) More to come Conjunctions with near-earth tail perigees of wind September 17, 1995. Best WIND near-tail crossing; GEOTAIL moving outward from evening to near midnight, and IMP-8 in solar wind in front on the dawn side. Sonde, Millstone coverage: 16 Sept. 2200 UT to 17 Sept. 0600 UT Time Sat. GSE (RE) GSM (RE) dNeutS yyyy ddd hh:mm X Y Z X Y Z (RE) 1995 259 20:36 wind -13.1 8.7 1.7 -13.1 8.9 -0.4 -1.6 1995 260 02:36 wind -15.3 0.1 2.0 -15.3 0.7 1.9 3.1 1995 260 08:36 wind -14.7 -8.5 1.9 -14.7 -6.1 6.2 6.7 1995 259 20:36 geotail 3.8 10.3 1.4 3.8 10.3 -1.2 N/A 1995 260 02:36 geotail -5.9 8.7 1.1 -5.9 8.6 -1.6 N/A 1995 260 08:36 geotail -12.6 2.3 0.2 -12.6 2.1 -1.1 -0.5 1995 260 02:36 imp8 22.3 -27.3 -0.6 22.3 -26.1 7.8 N/A August 20, 1995. Close in WIND tail crossing: GEOTAIL directly in front monitoring the solar wind, IMP-8 in dawn-flank of tail or dawn magnetosheath. Sondrestrom, Millstone coverage: 19 Aug. 2200 to 20 Aug. 0600 (should extend to ~15 UT) Time Sat. GSE (RE) GSM (RE) dNeutS yyyy ddd hh:mm X Y Z X Y Z (RE) 1995 232 01:36 wind -4.1 8.9 0.1 -4.1 8.7 -1.7 N/A 1995 232 07:36 wind -7.8 -2.6 0.5 -7.8 -2.1 1.6 N/A 1995 232 13:36 wind -3.5 -12.7 0.3 -3.5 -11.0 6.3 N/A 1995 232 01:36 geotail 24.2 -3.4 -1.7 24.2 -3.7 -1.0 N/A 1995 232 07:36 geotail 22.0 1.1 -1.1 22.0 0.5 -1.4 N/A 1995 232 13:36 geotail 18.4 5.5 -0.3 18.4 4.6 -2.9 N/A 1995 232 07:36 imp8 -9.7 -32.2 23.1 -9.7 -18.1 35.2 N/A November 29, 1995. Solstice WIND tail crossing: GEOTAIL in dawn magnetosheath or boundary layer, IMP-8 further back in dawn magnetosheath or boundary layer. (Millstone will cover period) (Sondrestrom coverage: 29 November 2000 to 30 November 0400) 1995 333 08:36 wind -13.4 7.0 0.0 -13.4 6.6 -2.4 1.7 1995 333 14:36 wind -13.0 -2.2 -0.9 -13.0 -2.4 -0.3 1.9 1995 333 20:36 wind -9.0 -10.8 -1.6 -9.0 -10.8 -1.6 N/A 1995 333 08:36 geotail -1.0 -21.4 -0.7 -1.0 -20.3 6.8 N/A 1995 333 14:36 geotail 3.9 -18.1 0.1 3.9 -17.5 4.7 N/A 1995 333 20:36 geotail 8.2 -12.8 0.8 8.2 -12.8 0.7 N/A 1995 333 14:36 imp8 -3.7 -28.9 -11.3 -3.7 -30.8 -3.4 N/A December 21, 1995. Solstice WIND near tail crossing: GEOTAIL moving towards dusk magnetosheath, IMP-8 crossing the tail (in the lobe?). Sondrestrom. Millstone coverage: 20 Dec. 2200 to 21 Dec. 0600 (move start to ~ 15 UT?) (EISCAT SAC has put a 45 hour CP1/CP4 operation around that passage) 1995 355 15:36 wind -10.7 10.9 -0.2 -10.7 10.8 -0.9 0.7 1995 355 21:36 wind -13.3 2.0 -1.0 -13.3 2.2 -0.6 2.9 1995 356 03:36 wind -12.3 -7.3 -1.5 -12.3 -7.2 -2.0 3.3 1995 355 15:36 geotail 9.9 -3.8 1.4 9.9 -3.7 1.6 N/A 1995 355 21:36 geotail 8.4 6.1 0.9 8.4 5.8 2.0 N/A 1995 356 03:36 geotail 2.0 12.7 -0.1 2.0 12.7 0.7 N/A 1995 355 21:36 imp8 -36.4 -5.7 7.1 -36.4 -6.9 5.9 9.3 Jan. 13, 1996. three sat. in tail: WIND near 14 Re, Geotail on dusk side further back, and IMP-8 about the same X as GEOTAIL, but nearer or perhaps outside tail boundary POLAR and CLUSTER? Sondrestrom, Millstone coverage: 12 Jan. 2000 to 13 Jan. 0400 (should extend to ~14 UT) 1996 13 03:48 wind -11.8 6.4 -1.1 -11.8 6.5 0.3 5.2 1996 13 09:48 wind -14.1 -2.7 -1.4 -14.1 -2.7 -1.3 3.0 1996 13 15:48 wind -13.1 -11.3 -1.4 -13.1 -11.1 -2.6 -1.1 1996 13 03:48 geotail -11.2 18.9 -2.7 -11.2 19.1 1.6 0.3 1996 13 09:48 geotail -16.1 18.3 -3.2 -16.1 18.2 -3.8 -4.3 1996 13 15:48 geotail -20.2 16.8 -3.5 -20.2 17.1 -1.6 -1.6 1996 13 09:48 IMP8 -18.9 28.0 20.3 -18.9 28.7 19.4 13.6 Two additional campaigns are being worked in conjunction with ISTP for February and in April (Nelson Maynard). Larry Lyons, Nelson Maynard +-------------------------------------------------------------------------+ |To add name to the mailing list, send a message to: editor at igpp.ucla.edu | |For message to whole GEM mailing list, send to: gem at igpp.ucla.edu | |For message to a specific working group (BL Campaign), send to: | | gem_field at igpp.ucla.edu (WG1); gem_boundary at igpp.ucla.edu (WG2); | | gem_current at igpp.ucla.edu (WG3); gem_data at igpp.ucla.edu (WG4) | | gem_ggcm at igpp.ucla.edu (WG5) | | gem_chair at igpp.ucla.edu (WG chairs, Odile and W. J. Hughes) | | | |URL of GEM Home Page: http://igpp.ucla.edu/gem/Welcome.html | |Please update your e-mail address. | |CAUTION: Do not send messages to gem at igpp.ucla.edu unless you want | | your message to go to everyone in the GEM mailing list! | +-------------------------------------------------------------------------+