THEMIS First Results and near future Introduction, THEMIS overview First THEMIS results from the tail THEMIS results in other regions Data availability Future activities

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

Near-Earth tail reconnection Localization: the case for “point” reconnection Angelopoulos et al., 1998 (Case study on localization) Nakamura et al., 2004 (Cluster statistics on localization) Scales: Vertical: 1.5-2 RE, Azimuthal: 2-3 RE Sharper gradient on duskside flank

Nagai 1991 results T = -0.01 x MLT**4 - 0.06 x MLT**3 + 1.16 x MLT**2 + 1.13 x MLT + 0.27 T delay time (minutes) at each MLT Here, 23 MLT is -1.0, 22 MLT is -2.0 24 MLT 0.27 min (not well bound by data, a statistical average) 23:32MLT 0.00 min (the center of the current wedge, average) 23 MLT 0.35 min (not well bound by data, a statistical average) 22 MLT 2.97 min 21 MLT 8.13 min 20 MLT 15.59 min

The 3D nature of the Rx process 0204UT JGR [Angelopoulos et al, 1995] Substorm Onset: ~0202UT Ygsm Xgsm 0215UT Ygsm

Mission overview D2925-10 @ CCAS BGS Release Operations UCB SST ESA EFIa EFIs FGM SCM Tspin=3s BGS D2925-10 @ CCAS Release Operations UCB Encapsulation & launch Probe instruments: ESA: ElectroStatic Analyzer (coIs: Carlson and McFadden) SST: Solid State Telescopes (coI: Larson) FGM: FluxGate Magnetometer (coIs: Glassmeier, Auster & Baumjohann) SCM: SearchCoil Magnetometer (coI: Roux) EFI: Electric Field Instrument (coI: Bonnell) Mission I&T UCB Ground Instrument I&T UCB

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 THEMIS glimpsed the tail in the middle of its commissioning phase, before moving towards the dusk sector. In an orbit designed to simulate routine science operations, it captured two substorms from a good vantage point. The THEMIS probes were arrayed like pearls on a string with end-to-end separation of 10Re. The middle probes (A, B, and D) were separated by ~ 0.25Re. In addition, the POLAR spacecraft was imaging the southern auroral oval. TH-C SUN THA X THB THC Z THD SUN POLAR

Courtesy: Parks and Fillingim 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 0.5MLT UVI uncertainty from POLAR wobble

From VIS: 2007_082_1008-1309_all.mov At 11:18:03-45UT. By 11:19:57UT. Auroras brighten @ 23MLT By 11:19:57UT. Auroras expand to 22MLT By 11:23:21UT No further westward expansion observed

Keograms from UVI

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 FAC jumps to 21 Apatenkov/Sergeev model: SCW Upward FAC jumps to 21.5MLT and stays there for >20 minutes

Classical mapping Tsyganenko 2001 mapping: THEMIS maps to 21.5 MLT (other models, or higher activity place thm to the West). 21.5MLT

Courtesy: J. Raeder (UNH) Simulation mapping OpenGGCM mapping: THEMIS just before simulation onset maps to ~22.5 MLT, i.e., right in the middle of expanding activation. Note: mapping evolves Courtesy: J. Raeder (UNH)

X Z Y B FAC By B sc 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 current sheet. This is consistent with THEMIS being at the westward edge of the WTS.

Moments Overview TH-D

Courtesy: L. Kepko (UNH) Vorticity in FAC coordinates From TH-D,B,A (inner) Check using different center probe From DBA, BAD, ABD Courtesy: L. Kepko (UNH)

Strangeway et al. SM11A observe similar signatures of FAST

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/min Maps to 10RE as 200km/s westward (250km/s along track) Observed speed in space (from time delays) is ~250km/s From 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

Tail 1 (Jan ’08 – Mar ’08) http://sscweb.gsfc.nasa.gov/tipsod/ 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/

FTEs on TH-D: Detail

Sphere -,+ Sheath Sibeck et al., SM 22B-08 Dissection of an FTE by THEMIS Sphere Dusk MP -,+ Sheath Sibeck et al., SM 22B-08

Phan et al., SM 22B-01 Magnetopause reconnection event (May 21) TH-B TH-C TH-C TH-D TH-D TH-E TH-A TH-E TH-A Phan et al., SM 22B-01

Magnetopause reconnection event, May 21 example - detail

Remote sensing of FTEs: dayside TCRs Liu Jiang, SM11A-0316 B D C E A

Scheduled Cluster-THEMIS coordination intervals 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

Data availability

First publications by instrument leads 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

Expect first substorm results to be reported in ICS-9 Anticipating an Exciting Tail Season Expect first substorm results to be reported in ICS-9

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