1. THEMIS Science Progress NASA/GSFC, Oct 26, 2007

2. March 23, 2007 Event “THEMIS captures the Expansion of a Substorm in space” Lead: Angelopoulos

3. First light: Nature’s welcome. Two substorms seen on March 23
DETAILED VIEW
THEMIS
TH-E
THE Y Y
TH-A Z
TH-B
TH-D X
TH-C
SUN
THA X
THB
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.
THC Z
THD
SUN
POLAR

4. THA-FGM FIT Data (3s) Available
TH-FGL Overview X: Y: Z:
____
THA-FGM FIT Data (3s) Available
Note:
Z=SMZ
Rxy rotated
X= - Ewd
POLAR UVI/VIS
Onset 10:58UT
Intensifications

5. From UVI At 11:18:26UT. By 11:19:40UT. By 11:23:21UT
Substorm 23MLT
By 11:19:40UT.
Auroras expand to 21.5MLT
By 11:23:21UT
Expansion slows down

6. 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

7. Hfrey_mar23_GBO_movie.mpg
smoke
New Auroral
Intensification
(Main, ~11:18UT)
Previous
Intensification (~11:10UT)

9. Summary, March 23 11:18 onset
First direct detection of Westward Traveling Surge motion in the magnetosphere
200km/s westward motion consistent with expectation from ground data
Expansion is motion of activity westward, flows are Earthward and duskward
Simultaneous inward and outward expansion of the injection
Azimuthal effects are dominant in this case
THEMIS tail alignments in 2008 will be able to resolve temporal relationship and relative motion of current disruption, dipolarization and particle
injections, one of the primary THEMIS objectives

10. May 20, 2007 Event “THEMIS satellites dissect and reconstruct magnetic flux ropes at the magnetopause: ” Lead: Sibeck

11. E C D
THA
THB

12. ESA
Electrons
RDFs

13. ESA
gmoms
Ni_all
Ti_all

14. First – ever detection of a detached FTE at the magnetopause
Modeling and reconstruction of flows, fields suggests FTE is isolated from magnetopause
THEMIS, with its string-of-pearls orbit offers a unique opportunity to differentiate between boundary layer waves and detached plasma structures such as this FTE A B E D C
X_gse
Y_gse
V_sh
dBxy

15. July 4, 2007 Event “THEMIS satellites detect extreme changes to the Earth-Sun boundary caused by interplanetary currents” Lead: Eastwood

16. Hot Flow Anomaly (HFA) detection
HFA Geometry
Hot Flow Anomaly (HFA) detection
A: Blue
B: Cyan
C: Green
D: Orange
E: Red
A – in solar wind
B, C, D, E – in magnetosheath
The discontinuity underlying the HFA had just reached the bow shock
The HFA had just started

17. What are Hot Flow Anomalies?
Questions:
Plasma physics
Ion heating – current sheet particle scattering or beam instabilities)?
Ions: multiple populations or single population?
Electrons – isotropic and ‘Maxwellian’ [Schwartz et al., 2000] – how are the electrons heated?
Magnetospheric physics – what is their impact on the magnetosphere?

18. First observation of HFA on both sides of the bow shock
Flow deflection, cavity forming, complicated series of magnetic field discontinuities
First observation of HFA on both sides of the bow shock

19. Simulations [Omidi and Sibeck, JGR 2007]
2.5D Global Hybrid simulation, courtesy Nick Omidi

20. Simulations [Omidi and Sibeck, JGR 2007]
2.5D Global Hybrid simulation, courtesy Nick Omidi

21. Propagation of pressure pulse down flanks
As the pressure pulse associated with the HFA propagates down the tail its signature moves from east to west (top to bottom) across the THEMIS magnetometer chain
Petersburg Alaska

22. First detection of the evolution of an HFA through the magnetopause and magnetosphere.
THEMIS is able to measure the evolution of particles and fields
Unremarkable solar wind features can have large implications for energy input to magnetosphere

23. Publications: SSR
Editors: J. Burch and C. T. Russell

24. Publications: GRL, Special Issue
Editors: M. Chen and N. Ostgaard

25. Publications: JGR, Special Issue
Editors: A. Battachargee, W. Baumjohann, Z. Pu

26. Science Events: Outlook
AGU meeting (Dec 10-14)
40 presentations to special session on multi-spacecraft observations (Mon-Tue)
Pre-AGU community engagement event under auspices of GEM
THEMIS data and software tools: tutorial for the community
SWT meeting (Dec 15, UCB)
SWT meeting (Apr 6-9, Southern CA)
First joint analysis of substorm events
Intl. Substorm Conference (ICS9) meeting (May 4-8, Graz)
First presentations of substorm events from THEMIS
Special issue at Annales Geophysicae
Joint THEMIS-Cluster Workshop, (October 2008, UNH)
Results from first year of THEMIS nominal science operations