1 THEMIS Inner Magnetosphere Review, Dec 20, 2008

• Summary of THEMIS results in the inner magnetosphere

• Future mission operations discussion:– Science targets

– What do we need to change (if anything)?

THEMIS in the inner magnetosphere:Review of current

2 THEMIS Inner Magnetosphere Review, Dec 20, 2008

THEMIS Extension (FY10,11,12)

3 THEMIS Inner Magnetosphere Review, Dec 20, 2008

Extended THEMIS Baseline (P3,P4,P5)

• At Inner Magnetosphere, Study Role of:– ULF/VLF/EMIC waves on ion, electron

energization/losses – Large electric fields on storm time ring current

• Result:– Comprehensive AC waves and E-fields models

• Using novel:– 0.1-2RE separations to resolve

temporal/spatial evolution of gradients– daily conjunctions: PFISR, S-DARN

P3 P4

P5

4 THEMIS Inner Magnetosphere Review, Dec 20, 2008

EMIC waves Usanova et al.,GRL, 2008

1

2

3

- Driven by SW Pdyn

- Confined to L=5-6.5

- Structured, with good ground-space correlation

- Potentially important for RB loss.

5 THEMIS Inner Magnetosphere Review, Dec 20, 2008

Ring Current

Ions ElectronsDst storm indexTH-B

TH-D

TH-B

TH-B

TH-D

TH-B

- Ions penetrate deep into the inner magnetosphere, and remain after storm.- Electrons also come close to Earth, but decay fast after storm recovery.

Wang et al.,GRL, 2008

6 THEMIS Inner Magnetosphere Review, Dec 20, 2008

TH-C

DBA

E

Ygse

Xgse

D

B

A

2000kmTH-C

DBA

E

Ygse

Xgse

D

B

A

2000km

D

B

A

2000km

Angelopoulos et al.,First Results from THEMIS,Space Sci. Reviews, 2008

V ~

350

km/s

Speed: 1MLT/min

Substorm InjectionWestward Propagation

97A

046

7 THEMIS Inner Magnetosphere Review, Dec 20, 2008

Injection Simulatedas localized pulse

Liu, Wenlon et al., JGR, 2008

8 THEMIS Inner Magnetosphere Review, Dec 20, 2008

Electrons, TH-A

Ions, TH-C, B, E

Plasma SheetInjections

Runov et al.,GRL, 2008

-Nose structure, temporal-Electron injection local, transient

9 THEMIS Inner Magnetosphere Review, Dec 20, 2008

Generation ofwhistler emissions

Li et al.,JGR, 2008

• Low and upper band chorus emissions correlate with 5-10keV electron anisotropy

– 10keV electrons at higher L-shells have sufficient anisotropy to generate observed wave power

– 1keV electrons can penetrate deep but don’t have the required anisotropy to generate chorus

– Higher plasma density results in higher amplitudes

10 THEMIS Inner Magnetosphere Review, Dec 20, 2008

Whistler emissionsCully et al.,GRL, 2008

• Localized, large amplitude chorus emissions– Bursts of sub-second duration– Greater than100mV/m– L~3.5-5.5; dMLT = 1-3 hrs

• Mean/average not good description of wave field

11 THEMIS Inner Magnetosphere Review, Dec 20, 2008

• KH wave seen by THC,B,D,A– Couples to ULF wave on TH-E

• Driven ULF wave is localized– Phase change 180o at peak amplitude

KH-wave driven FLRs: Agapitov et al., JGR, 2008

12 THEMIS Inner Magnetosphere Review, Dec 20, 2008

FLR Polarisation

• as

Data – Electric Field Data – Magnetic Field

Model – Electric Field - m1(poloidal)

Model – Magnetic Field - m1

Model – Electric Field - m2(toroidal)

Model – Magnetic Field - m2

• Polarisation of Pc5 ULF changes along THEMIS orbit.

• Agreement with twisted eigenmode solutions (Rankin et al., Kabin et al.)

• Importance of FLR in structure?

[Sarris et al., 2008]

13 THEMIS Inner Magnetosphere Review, Dec 20, 2008

FLR Statistics

Occurrence rates.

Pc4

Pc5

Poloidal Toroidal

Pc4

Pc5

Poloidal Toroidal

[Liu et al., 2008]

Wave Power.

• Wave power shows absence of storm time afternoon side Pc4-5 power.

14 THEMIS Inner Magnetosphere Review, Dec 20, 2008

Summary• THEMIS already presents significant present capability to measure:

– Waves, particles and their interactions from the radiation beltsout to the plasma sheet

• Continuous operations from solar min to solar max

• Can provide plasma sheet sources, measure ULF, EMIC waves for studying radiation belt dynamics

• Can provide rapid crosses of radiation belt electron phase space density

• Multiple satellites can provide information on phase and group velocity

• String of pearls configuration can resolve spatio-temporal ambiguities

• Critical importance will be storms in continuing and extended mission

15 THEMIS Inner Magnetosphere Review, Dec 20, 2008

Instrument overview

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)

SST

ESA

EFIa

EFIs

FGM

SCM

Tspin=3s

16 THEMIS Inner Magnetosphere Review, Dec 20, 2008

Extended THEMIS Baseline (P3,P4,P5)

• At the Magnetotail, Study:– Nature of the near-Earth current sheet– Dissipation of bursty fast flows

• Result:– Ability to map and model key

instability region

2010-04-10 00:00:00

P3P4

P5

X

Z

X

Y

• With first ever:– Simultaneous dR-dZ separations, 0.1-1RE

– Clustered orbits study the 8-12RE region

FAST

17 THEMIS Inner Magnetosphere Review, Dec 20, 2008

Extended THEMIS Baseline (P3,P4,P5)

• At Subsolar Magnetopause, study:– Asymmetric reconnection: dynamics, evolution and

role of cold ions– Internal FTE structure and electron acceleration

• Result:– Hall-physics of subsolar magneto-pause reconnection,

paves way to MMS

2010-04-10 00:00:00

P3P4

P5 X

Z

[THEMISCoast PhaseMozer et al.GRL]

• Using novel:– Simultaneous dR-dZ separations at 0.1-

0.5RE monitor inflow and outflow– Cluster-like separations at subsolar region

18 THEMIS Inner Magnetosphere Review, Dec 20, 2008

Data availability