Conjugate response of the dayside magnetopause and dawn/dusk flanks using Cluster-THEMIS conjunctions and Ground based observations M 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.

l Some Themis events analysed separately l 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 l 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 l Comparative studies of dynamic response Generation 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 l Comparative Cluster-Double star configurations have been studied previously Included 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 TC-1 Cluster C4 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 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 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 conjunctions Configurations 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 FTEs Brief Survey of highlighted conjunctions : full 2007 list up to end of June. Need review of July 2007 and 2008 Additional Bow Shock conjunctions; or mixed BS-MP coordination

14 June: close conjunction all 10 s/c * Fitted Pram=2nPa Matches TH crossings TH-A and TC-1 same UT MP cut at Z=-4 Re No 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. Themis s/c sequence E

28 June: Solar Wind: north IMF; turns –By; steady Pram Geotail: 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 Pram Geotail: 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 Pram Geotail: dawnside magnetosheath, tailward of cluster Early train of FTEs at Cluster. * TH Z=-1 Re TC-1 Z=-5 Re Cluster 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 SW Solar Wind: IMF reversal to south Pram pulse increase Geotail: 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 Z=-15 Re

6 June: Solar Wind: IMF By, steady Pram Geotail:

30 May: Solar Wind: IMF By, steady Pram Geotail:

l Event highlights