AGU F07, SD13D-01 1 Dec 11, 2007
• First THEMIS results from the tail
• THEMIS results in other regions
• Data availability
(abridged, from Angelopoulos, Fall ’07 AGU, SM13D01)
THEMIS First Results and Near Future Plans
AGU F07, SD13D-01 2 Dec 11, 2007
THEMIS Mission elements
Probe conjunctions along Sun-Earth line recur once per 4 days over North America.
Ground based observatories completely cover North American sector; determine
auroral breakup within 1-3s …
… while THEMIS’s space-based probes determine onset of Current Disruption and
Reconnection each within <10s.
: Ground Based Observatory
AGU F07, SD13D-01 3 Dec 11, 2007
THEMIS
POLAR
http://sscweb.gsfc.nasa.gov/tipsod
SUNSUN
X
Y
Z
X
YZ
DETAILED VIEW
THC
THE
THDTHB
THASUNSUN
First light: Nature’s welcome.Two substorms seen on March 23
TH-CTH-D
TH-BTH-A
TH-E
AGU F07, SD13D-01 4 Dec 11, 2007
AGU F07, SD13D-01 5 Dec 11, 2007
At 11:18:26UT.Substorm intensification @ 23MLT
By 11:19:40UT.Auroras expand to 21.5MLT
By 11:23:21UTNot much further expansion
From UVI
Consistent with VIS due to 0.5MLTUVI uncertainty from POLAR wobble
Courtesy: Parks and Fillingim
AGU F07, SD13D-01 6 Dec 11, 2007
At 11:18:03-45UT.Auroras brighten @ 23MLT
By 11:19:57UT.Auroras expand to 22MLT
By 11:23:21UTNo further westward expansion observed
From VIS: 2007_082_1008-1309_all.mov
AGU F07, SD13D-01 7 Dec 11, 2007
Keograms from UVI
AGU F07, SD13D-01 8 Dec 11, 2007
At 11:18:42UT. From:3_23_07_mosaic.movOnset at 11:18:42UT@ 23MLT (see Mende et al.)
AGU F07, SD13D-01 9 Dec 11, 2007
Apatenkov/Sergeev model:SCW Upward FACjumps to 21.5MLT andstays there for >20 minutes
AGU F07, SD13D-01 10 Dec 11, 2007
Tsyganenko 2001mapping: THEMIS maps to21.5 MLT (other models, orhigher activity place thm tothe West).
21.5MLT
Classical mapping
AGU F07, SD13D-01 11 Dec 11, 2007
OpenGGCM mapping:THEMIS just before simulationonset maps to ~22.5 MLT, i.e.,right in the middle of expandingactivation. Note: mapping evolves
Simulation mapping
Courtesy: J. Raeder (UNH)
AGU F07, SD13D-01 12 Dec 11, 2007
FAC
B
By
X
Z
Y
Assuming an outward plasma sheet expansion (evidenced by the |Bx|reduction - interpreted as a diamagnetic effect) the FAC is a pair ofoppositely directed current sheets, embeded in an overall outward currentsheet. This is consistent with THEMIS being at the westward edge of the WTS.
B
sc
AGU F07, SD13D-01 13 Dec 11, 2007
MomentsOverviewTH-D
AGU F07, SD13D-01 14 Dec 11, 2007
AGU F07, SD13D-01 15 Dec 11, 2007
Vorticity in FAC coordinatesFrom TH-D,B,A (inner)
Check using different center probeFrom DBA, BAD, ABD
Courtesy: L. Kepko (UNH)
AGU F07, SD13D-01 16 Dec 11, 2007
Strangeway et al. SM11Aobserve similar signatures of FAST
AGU F07, SD13D-01 17 Dec 11, 2007
Conclusions, March 23 event:
1. 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?
AGU F07, SD13D-01 18 Dec 11, 2007
Examples of THEMIS capabilities
Mende et al, GRL 2007
AGU F07, SD13D-01 19 Dec 11, 2007
Coast, Placement and Tail Phases
Coast phase dayside (May-Aug ’07)
Placement (Sep-Dec ’07)
Tail 1 (Jan ’08 – Mar ’08)http://sscweb.gsfc.nasa.gov/tipsod/
http://sscweb.gsfc.nasa.gov/tipsod/
AGU F07, SD13D-01 20 Dec 11, 2007
FTEs on TH-D: Detail
AGU F07, SD13D-01 21 Dec 11, 2007
40
0
THEMIS-E
40
0
THEMIS-D
40
0
THEMIS-C
40
0
THEMIS-A
40
022:00 22:01 22:02 22:03 22:04
UT
THEMIS-B
THEMIS May 20, 2007
-40
0
40THEMIS-D
13.0
12.5
12.0
11.5
11.0
10.5
10.0
8.0 7.5 7.0 6.5 6.0 5.5 5.0
X (RE)
Magnetosphere
Magnetosheath
30 nT
20 nT
10 nT13.0
12.5
12.0
11.5
11.0
10.5
10.0
8.0 7.5 7.0 6.5 6.0 5.5 5.0
X (RE)
A
ED
C
B
Δ Bxy
Dusk MP
Sphere
Sheath
-,+
Dissection of an FTE by THEMIS
Sibeck et al., SM 22B-08
AGU F07, SD13D-01 22 Dec 11, 2007
Magnetopause reconnection event(May 21)
TH-BTH-CTH-D
TH-ETH-A
TH-B
TH-C
TH-D
TH-E
TH-A
Phan et al., SM 22B-01
AGU F07, SD13D-01 23 Dec 11, 2007
Magnetopause reconnection event,May 21 example - detail
AGU F07, SD13D-01 24 Dec 11, 2007
Remote sensing of FTEs: dayside TCRs
BDCE
A
Liu Jiang, SM11A-0316
AGU F07, SD13D-01 25 Dec 11, 2007
Upcoming Tail Season Activities
Cluster-THEMIS, top view Cluster-THEMIS, side view
Scheduled Cluster-THEMIS coordination intervalsScheduled AMISR, Sondestrom radar scansSuperDARN in THEMIS mode, w/ added midlat radars
AGU F07, SD13D-01 26 Dec 11, 2007
Data availability
AGU F07, SD13D-01 27 Dec 11, 2007
• 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
THEMIS Data Policy
Top Related