*************************** ** THE GEM MESSENGER ** *************************** Volume 6, Number 17 April 26, 1996 --------------------------- GEM T/S WG-1 CALL FOR INPUT --------------------------- From: "Larry Lyons" TAIL/SUBSTORM CAMPAIGN WG 1: SUBSTORM SIGNATURES; IDENTIFICATION, LOCATION, AND TIMING SNOWMASS 96 PLANS A CALL FOR DATA!! WG-1 is data oriented with a focus of defining an accurate spatial and temporal description of the substorm process in the magnetosphere and ionosphere. The timing of events in one region relative to another is critical to address the questions of cause and effect. It is our intent to assemble definitive data sets that can address key science issues and with which models of substorm processes can be tested and validated. A large amount of data have been supplied for past events, some of which are available through Web home pages. We are extremely pleased with the cooperation of all who have sent data. We would like to reiterate, as we proceed through analysis of previous sets and the gathering of new sets, that the studies need to remain coordinated. Rules of the road should be the same as those on a number of recent satellite programs: _____________________________ If you use someone's data, offer that person a chance to be part of the study, to have the option of participating as a co-author or to add any necessary and pertinent caveats. Keep the data suppliers and coordinators informed as to who is pursuing what topics and events. _____________________________ At SNOWMASS 96 we intend to have four working group sessions. The first one and half will be devoted to reporting on the status of the analyses of previous GEM events. These will be led by the event coordinators: Hughes (CRRES), Maynard (11-14 January 1994), Lyons (March 93), and Rodger (March 95). In addition, Lui will discuss data from 02-08 UT on 9 Feb. 1995 (0430 onset). Lui would like to encourage interest from the GEM ground-based community in this ISTP event and to receive additional ground and synchronous data for the event. Please contact your event coordinator relative to papers written on these periods or new discussion topics based on these data. We would like to close out several of these periods at this meeting. The remaining two and a half workshop periods will be devoted to assembling and discussing new data from the WIND perigee passes which was started at the fall miniworkshop. A list of these passes follows. NOTE THAT THREE NEW PERIGEE PASSES HAVE BEEN ADDED, TWO OF WHICH WILL HAVE POLAR DATA. We would suggest concentrating on the September and January events (which we know to contain substorm activity) and the three new ones involving POLAR. We also welcome interest in the December event if there is any, especially since EISCAT had scheduled extensive coverage. Please respond to Nelson Maynard (nmaynard at mrcnh.com) as to who has data for these event periods, substorm onset times (to the degree that you can define it), and availibility for discussion at Snowmass. A followup message will be sent in early June to define common plotting intervals based on your respones. The tutorial sponsored by Working Group 1 will be split between George Parks and Lou Frank who will present capabilities of and results from their imagers on POLAR. Conjunctions with near-earth tail perigees of wind 1. 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. STATUS: Good substorm activity. Discussed at Fall AGU Mini-workshop - Jim Slavin of GSFC to coordinate analyses. 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 2. November 29, 1995. Solstice WIND tail crossing: GEOTAIL in dawn magnetosheath or boundary layer, IMP-8 further back in dawn magnetosheath or boundary layer. Status: Unknown (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 3. December 21, 1995. Solstice WIND near tail crossing: GEOTAIL moving towards dusk magnetosheath, IMP-8 crossing the tail (in the lobe?). STATUS: Very quiet. Was there anything interesting??? Sondrestrom. Millstone coverage: 20 Dec. 2200 to 21 Dec. 0600 (EISCAT SAC 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 4. 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 STATUS: Good activity. Suggest that this is an event to focus on. 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 NEW EVENTS!! POLAR data is (will be) available for the first and third events that follow. The following three events continue the series of WIND perigee passes that have potential for excellent substorm studies. 5. 1996-087 03/27-28 1200 - 0700UT Satellite positions: Wind and Geotail - in near tail; Interball and IMP8 - solar wind; Geosync and DMSP will also be usefull; Polar pass through the auroral zone maps to Russian sector in the 1700 to 2000 UT time frame. 6. 1996-109 04/17-18 2000 - 1400UT Satellite positions: Wind and Geotail - in near tail (dusk flank to past midnight); IMP8 - solar wind; Interball - high lat magnetosheath; Geosync and DMSP also usefull. No Polar coverage except possibly in situ fields instruments and limited particle instruments due to spacecraft turn-around maneuver. Polar auroral zone pass 20-00UT on 17 April 7. 1996-130 05/9-10 1800 - 1500UT Satellite positions: Wind and Geotail - in near tail; Interball - in auroral zone and high lat mantle; IMP8 - near bow shock (probable solar wind coverage); Geosync and DMSP also useful. Polar pass through nightside auroral zones 18-22UT (9 May), dayside cusp 23-05UT, mantle + auroral zone imaging 05-12UT, auroral zone pass 11-15UT The last event is particularly interesting because of the close spacing of WIND and GEOTAIL as they cross from 2200LT to midnight between 10 and 15 Re near from 0000 to 0500UT on 10 May. In the event 6, WIND and GEOTAIL also are close together in this region but at later UT times. See you at Snowmass! Nelson Maynard (nmaynard at mrcnh.com) Larry Lyons (larry_lyons at qmail2.aero.org) +-------------------------------------------------------------------------+ |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! | +-------------------------------------------------------------------------+