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Some Themis events analysed separately Comparative studies of FTEs and other transient phenomena

Conjugate response of the dayside magnetopause and dawn/dusk flanks using Cluster-THEMIS conjunctions and Ground based observations M W Dunlop, Q-H. Zhang

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Some Themis events analysed separately Comparative studies of FTEs and other transient phenomena

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  1. 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.

  2. Multi-point study themes: dayside boundary • 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 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 • Comparative Cluster-Double star configurations have been studied previously • Included development and use of multi spacecraft analysis tools

  3. Cooling model FTE C4 Cluster/DSP TC1 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. Cluster TC-1 • 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.

  4. 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)

  5. 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). • 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.

  6. 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: • 28 May: • 28 June: • 3 May: • 21 June: • 23 April: • 1 May: • 6 June: • 27 April: • 30 May:

  7. 14 June: close conjunction all 10 s/c • 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. Fitted Pram=2nPa Matches TH crossings TH-A and TC-1 same UT Themis s/c sequence E MP cut at Z=-4 Re No fit to TC and Cluster positions *

  8. 28 June: Solar Wind: north IMF; turns –By; steady Pram Geotail: in magnetotail Mirror modes? MP not fitted. * Cluster/TH Z=-2 Re TC-1 Z=-5 Re. Flank BL + FTEs.

  9. 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. *

  10. 28 May: - multiple crossings Check orientation and motion possible MP ripples Cluster/TH Z=-1 Re TC-1 Z=-5 Re. *

  11. 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. *

  12. 21 June: GB - FTE Solar Wind: variable IMF high Pram; sudden decrease: 10:15 UT MP not fitted. All ~Z=-5 Re.

  13. 21 June: SW structure in m’sheath Compressed magnetosphere: Pram; sudden decrease: 10:15 UT MP not fitted. All ~Z=-5 Re.

  14. 23 April: Cluster in SW Solar Wind: IMF reversal to south Pram pulse increase Geotail: conjunction with Cluster

  15. 27 April: MP motion – missing Themis data? Solar Wind: IMF -By, steady increasing Pram Geotail: dawnside, tail magnetosheath All s/c near equatorial *

  16. 1 May: Solar Wind: variable IMF, low Pram Geotail: in magnetotail Cluster @ Z=-15 Re

  17. 6 June: Solar Wind: IMF By, steady Pram Geotail:

  18. 30 May: Solar Wind: IMF By, steady Pram Geotail:

  19. Event highlights

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