Conjugate response of the dayside magnetopause and dawn/dusk flanks using Cluster-THEMIS conjunctions

and Ground based observationsM W Dunlop, Q-H. Zhang

M G G T Taylor, Y Bogdanova, J Berchem, D Constantinescu, J Eastwood, P Escoubet,

A Fazakerley, H Frey, H Hasegawa, B Lavraud, Z-Y Pu, C Shen, D Sibeck, M Volverk,

J Wild, J. Wang, E. Panov, J-K. Shi.

ISSI team: membership as above.

Selection of co-ordinated events between Themis, Double star and Cluster.

Covering the Epoch: April-July 2007• Cluster at large (multi-scale configuration) on dawn-side and flank

• Themis in ‘string of pearls’ on dusk-side and flank

• Double Star TC-1 covers a few hours around local noon

Periodic coverage with Geotail.

Conjunctions occur over the whole range of local time at both high and low latitudes.

Some Themis events analysed separately

Comparative studies of FTEs and other transient phenomena Ability to cover both sides of the magnetopause simultaneously

Potential to probe X-line extent, reconnection flow distribution and IMF Bz and By effects

Magnetopause boundary layer and plasma sheet Dawn/dusk flanks and at high and low latitudes

Comparative effects of lobe reconnection and K-H instability (northward IMF) on plasma sheet

Extent of behaviour along the magnetopause and relation to ground or ULF signatures

Comparative studies of dynamic responseGeneration of boundary and ULF waves at and inside the magnetopause

Global magnetopause motion identified from wide LT coverage

Close monitoring of response to Solar Wind: pressure pulses or IMF

Comparative Cluster-Double star configurations have been studied previouslyIncluded development and use of multi spacecraft analysis tools

Multi-point study themes: dayside boundary

Cluster-Double Star conjunctions I:

Dunlop et al 2005, 2007, 2008, Wang et al. 2006, Raeder et al.2006, Fear et al.2007, Wang et al.2007.

TC-1

ClusterC4

TC1

Cooling model

Cluster/DSP

FTE

• Coordination between Cluster and Double star lying north and south of the sub-solar point respectively: reconnection line at low latitude generating series of opposite FTEs.

• Observation of both moving flux tube branches simultaneously

• Evidence for asymmetric extent of the LLBL (north/south)

• Reversal in IMF – reconnection onset, change in (extent of) MP BL.

• Also coordination with Geotail and survey of FTE motions (Cooling)

• Global MHD: dipole tilt dependence, controlling occurrence.

• FT shape and sampling) dependent on location and conditions.

Cluster-Double Star conjunctions V:

E-M fields and waves in a thin magnetopause

Silin et al. 2005, Trines et al. 2007.

• Multi-spacecraft sampling of electrostatic solitons and zonal flows

• Time shifted traces, in LMN, show burst of DC and AC E field in the magnetospheric side of the MP.

• Evidence of electrostatic structures supporting solitary drift modes running down the density gradient

• Statistics of wave power in the boundary (higher outbound)

• During April/May TC-1 lies nearer noon and Cluster exits into the magnetosheath at the dawn terminator.

• The five THEMIS spacecraft in their string of pearls repeatedly skim the magnetopause at the dusk terminator.

• The middle panel shows orbit track segments within 2 hrs of a nominal magnetopause March to March 2007-8.

• Nearly the whole of the magnetopause is potentially covered:

THEMIS (black) scans the dusk-side

Cluster scans the dawn-side

TC-1 moves midway between them in LT.

Themis-Cluster-Double Star conjunctionsConfigurations of the five Themis (red), four Cluster (blue), Double Star TC-1 (light blue) and Geotail (cyan) spacecraft in April 2007 (left) and June 2007 (right).

• 14 June:

• 28 May:

• 28 June:

• 3 May:

• 21 June:

• 23 April:

• 1 May:

• 6 June:

• 27 April:

• 30 May:

MP morphology and FTEsBrief Survey of highlighted conjunctions : full 2007 list up to end of June.Need review of July 2007 and 2008Additional Bow Shock conjunctions; or mixed BS-MP coordination

14 June: close conjunction all 10 s/c

*

Fitted Pram=2nPaMatches TH crossingsTH-A and TC-1 same UT

MP cut at Z=-4 ReNo fit to TC and Cluster positions

Solar Wind: IMF+By, steady Pram (increasing)Geotail: inside dawn flank m’sphere, adjacent to Cluster• Possible FTEs on all s/c.• East-west motions.

Themiss/c sequence

E

28 June: Solar Wind: north IMF; turns–By; steady PramGeotail: in magnetotail

MP not fitted.

*

Cluster/TH Z=-2 Re TC-1 Z=-5 Re.

Mirror modes?

Flank BL + FTEs.

28 May: fast MP motion

Solar Wind: N/S IMF, low PramGeotail: in magnetotail

*Cluster/TH Z=-1 Re TC-1 Z=-5 Re.

28 May: - multiple crossings

Check orientation and motion possible MP ripples

*Cluster/TH Z=-1 Re TC-1 Z=-5 Re.

3 May: MP motion

east-west FTEs

Solar Wind: IMF –By(IMF turning northward), steady PramGeotail: dawnside magnetosheath, tailward of clusterEarly train of FTEs at Cluster.

*

TH Z=-1 Re TC-1 Z=-5 ReCluster Z=-12 Re.

21 June: GB - FTE

Solar Wind: variable IMF

high Pram; sudden decrease: 10:15 UT

All ~Z=-5 Re.

MP not fitted.

21 June: SW structure in m’sheath

Compressed magnetosphere:

Pram; sudden decrease: 10:15 UT

All ~Z=-5 Re.

MP not fitted.

23 April: Cluster in SWSolar Wind: IMF reversal to south Pram pulse increaseGeotail: conjunction with Cluster

27 April: MP motion – missing Themis data?

Solar Wind: IMF -By, steady increasing Pram

Geotail: dawnside, tail magnetosheath

All s/c near equatorial

*

1 May:

Solar Wind: variable IMF, low Pram

Geotail: in magnetotail

Cluster @ Z=-15 Re

6 June: Solar Wind: IMF By, steady Pram

Geotail:

30 May: Solar Wind: IMF By, steady Pram

Geotail:

Event highlights