AGU F07, SD13D-01 1 Dec 11, 2007

• Introduction, THEMIS overview

• First THEMIS results from the tail

• THEMIS results in other regions

• Data availability

• Future activities

THEMIS First Results and near future

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

Near-Earth tail reconnectionLocalization: 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

AGU F07, SD13D-01 4 Dec 11, 2007

Nagai 1991 resultsT = -0.01 x MLT**4 - 0.06 x MLT**3 + 1.16 x MLT**2 + 1.13 x MLT + 0.27T delay time (minutes) at each MLTHere, 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 min21 MLT 8.13 min20 MLT 15.59 min

AGU F07, SD13D-01 5 Dec 11, 2007

The 3D nature of the Rx process

Xgsm

Ygs

mY

gsm

JGR [Angelopoulos et al, 1995]

Substorm Onset: ~0202UT

0204UT

0215UT

AGU F07, SD13D-01 6 Dec 11, 2007

Mission overview

Instrument I&TUCB

Mission I&TUCB

Encapsulation

& launch

BGS

OperationsUCB

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)

Ground

SST

ESA

EFIa

EFIs

FGM

SCM

Tspin=3s

Release

D2

925

-10

@ C

CA

S

AGU F07, SD13D-01 7 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 8 Dec 11, 2007

AGU F07, SD13D-01 9 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 10 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 11 Dec 11, 2007

Keograms from UVI

AGU F07, SD13D-01 12 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 13 Dec 11, 2007

Apatenkov/Sergeev model:SCW Upward FACjumps to 21.5MLT andstays there for >20 minutes

AGU F07, SD13D-01 14 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 15 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 16 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 17 Dec 11, 2007

MomentsOverviewTH-D

AGU F07, SD13D-01 18 Dec 11, 2007

AGU F07, SD13D-01 19 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 20 Dec 11, 2007

Strangeway et al. SM11Aobserve similar signatures of FAST

AGU F07, SD13D-01 21 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 22 Dec 11, 2007

Examples of THEMIS capabilities

Mende et al, GRL 2007

AGU F07, SD13D-01 23 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 24 Dec 11, 2007

FTEs on TH-D: Detail

AGU F07, SD13D-01 25 Dec 11, 2007

40

0

B (

nT

)

THEMIS-E

40

0

B (

nT

)

THEMIS-D

40

0

B (

nT

) THEMIS-C

40

0

B (

nT

)

THEMIS-A

40

0

B (

nT

)

22:00 22:01 22:02 22:03 22:04UT

THEMIS-B

THEMIS May 20, 2007

-40

0

40

Bx (

nT

)

THEMIS-D

13.0

12.5

12.0

11.5

11.0

10.5

10.0

Y (

R E)

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

Y (

R E)

8.0 7.5 7.0 6.5 6.0 5.5 5.0

X (RE)

A

ED

C

B

Bxy

Dusk MP

Sphere

Sheath

-,+

Dissection of an FTE by THEMIS

Sibeck et al., SM 22B-08

AGU F07, SD13D-01 26 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 27 Dec 11, 2007

Magnetopause reconnection event,May 21 example - detail

AGU F07, SD13D-01 28 Dec 11, 2007

Remote sensing of FTEs: dayside TCRs

BDCE

A

Liu Jiang, SM11A-0316

AGU F07, SD13D-01 29 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 30 Dec 11, 2007

Data availability

AGU F07, SD13D-01 31 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

AGU F07, SD13D-01 32 Dec 11, 2007

Anticipating an Exciting Tail Season

Expect first substorm results to be reported in ICS-9

AGU F07, SD13D-01 33 Dec 11, 2007

The fun has just begun!

Do not miss out!

Join the THEMIS society!