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THEMIS First Results and Near Future Plans. First THEMIS results from the tail THEMIS results in other regions Data availability (abridged, from Angelopoulos, Fall ’07 AGU, SM13D01). : Ground Based Observatory. THEMIS Mission elements.
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THEMIS First Results and Near Future Plans • First THEMIS results from the tail • THEMIS results in other regions • Data availability (abridged, from Angelopoulos, Fall ’07 AGU, SM13D01)
: Ground Based Observatory THEMIS Mission elements Probe conjunctions along Sun-Earth line recur once per 4 days over North America. … while THEMIS’s space-based probes determine onset of Current Disruption and Reconnection each within <10s. Ground based observatories completely cover North American sector; determine auroral breakup within 1-3s …
First light: Nature’s welcome. Two substorms seen on March 23 http://sscweb.gsfc.nasa.gov/tipsod DETAILED VIEW THEMIS TH-E THE Y Y TH-A Z TH-B TH-D X TH-C SUN THA THB X THC THD Z SUN POLAR
From UVI Courtesy: Parks and Fillingim At 11:18:26UT. Substorm intensification @ 23MLT By 11:19:40UT. Auroras expand to 21.5MLT By 11:23:21UT Not much further expansion Consistent with VIS due to 0.5MLTUVI uncertainty from POLAR wobble
From VIS: 2007_082_1008-1309_all.mov At 11:18:03-45UT. Auroras brighten @ 23MLT By 11:19:57UT. Auroras expand to 22MLT By 11:23:21UT No further westward expansion observed
At 11:18:42UT. From: 3_23_07_mosaic.mov Onset at 11:18:42UT@ 23MLT (see Mende et al.)
Apatenkov/Sergeev model:SCW Upward FACjumps to 21.5MLT andstays there for >20 minutes
Classical mapping Tsyganenko 2001mapping: THEMIS maps to21.5 MLT (other models, orhigher activity place thm tothe West). 21.5MLT
Simulation mapping OpenGGCM mapping:THEMIS just before simulation onset maps to ~22.5 MLT, i.e.,right in the middle of expandingactivation. Note: mapping evolves Courtesy: J. Raeder (UNH)
Z Y X B FAC By sc B Assuming an outward plasma sheet expansion (evidenced by the |Bx| reduction - interpreted as a diamagnetic effect) the FAC is a pair of oppositely directed current sheets, embeded in an overall outward currentsheet. This is consistent with THEMIS being at the westward edge of the WTS.
Moments Overview TH-D
Vorticity in FAC coordinates From TH-D,B,A (inner) Check using different center probe From DBA, BAD, ABD Courtesy: L. Kepko (UNH)
Conclusions, March 23 event: • Measured expansion is much faster than previously measured locally but agrees with expectations from statistical averages First time it has been observed by nearby satellites. • Expansion speed on the ground ~ 1 MLT hrs/minMaps to 10RE as 200km/s westward (250km/s along track) • Observed speed in space (from time delays) is ~250km/sFrom 10RE it maps on the ground to ~1 MLT hrs/min • Orientation of expansion needs further investigation (under way)Use remote sensing and finite gyroradius techniques • Note: is was no continuous expansion of the WTS.A new activation appeared Westward of an old one.Likely the norm?
Examples of THEMIS capabilities Mende et al, GRL 2007
Coast, Placement and Tail Phases Coast phase dayside (May-Aug ’07) http://sscweb.gsfc.nasa.gov/tipsod/ Placement (Sep-Dec ’07) Tail 1 (Jan ’08 – Mar ’08) http://sscweb.gsfc.nasa.gov/tipsod/
Dissection of an FTE by THEMIS Sphere Dusk MP -,+ Sheath Sibeck et al., SM 22B-08
Magnetopause reconnection event(May 21) TH-B TH-B TH-C TH-C TH-D TH-D TH-E TH-A TH-E TH-A Phan et al., SM 22B-01
Remote sensing of FTEs: dayside TCRs Liu Jiang, SM11A-0316 B D C E A
Upcoming Tail Season Activities Scheduled Cluster-THEMIS coordination intervals Scheduled AMISR, Sondestrom radar scans SuperDARN in THEMIS mode, w/ added midlat radars Cluster-THEMIS, side view Cluster-THEMIS, top view
THEMIS Data Policy • Open data policy • Data on the street only 2 weeks after collection • Also, preliminary calibrations and overview plots • Also, software for analysis available • Credits. Always credit: NAS5-02099 • Strongly recommend to consult PI/coIs on data before study • Editors will be requested to ensure above have been implemented. • First publications by instrument leads • Space Science Reviews papers • First data papers within • One compendium, demonstrates instrument and use of data • GRL special issue on first science results • Community • Tag team with individual instrument leads to learn use of data • Engage in scientific discussions with coIs • Acknowledgement sufficient, if for use of data alone • Co-author instrument providers if helpful in data interpretation