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Observations and modeling of the injection during March 23rd event. Wenlong Liu 1 , X. Li 1 , T. Sarris 1 , C. Cully 1 , R. Ergun 1 , V. Angelopoulos 2 , D. Larson 2 1 LASP, University of Colorado at Boulder, CO 2 SSL, University of California, Berkeley, CA Thanks to SST, FGM and LANL Team.
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Observations and modeling of the injection during March 23rd event Wenlong Liu1, X. Li1, T. Sarris1, C. Cully1, R. Ergun1, V. Angelopoulos2, D. Larson2 1 LASP, University of Colorado at Boulder, CO 2 SSL, University of California, Berkeley, CA Thanks to SST,FGM and LANL Team
03/23/2007 11:28 Goes 11 1989-046 Geotail LANL-97A THEMIS Cluster
Proton flux enhancement in high energy range (>100keV). THEMIS-C SST FGM X Y Z 28 keV 134 keV 395 keV THEMIS-D SST FGM Clear dipolarization and injections signatures with a propagation or expanding speed of 200~300 km/s along GSM y direction (5~8 degree/minute azimuthally). THEMIS-B SST FGM THEMIS-A SST FGM c THEMIS-E SST FGM D B A GSM x-y E
FGM and SST ion observations of THEMIS C A not-so-clear dipolarization signature was observed by THEMIS C within strong field fluctuations, which might correspond to this injection.
SST ion and electron raw data THC Ion thc_psif_en Weak electron enhancement in THC THC Electron thc_pser_006_en THD Iont thc_psif_en No injection in THD THD Electron thd_pser_006_en SST electron data are smoothed from ‘ser_006’ data set
LANL-Electron LANL-Proton Drift Westward Drift Eastward Duskside LANL-97A Midnight 1989-046 Dawnside first electron injection at 11:22 first ion injection at 11:20 The center of injection was between the local times of ‘LANL-97A’ and ‘1949-046’.
Timing between THEMIS and LANL Time sequence: THEMIS C -> THEMIS D -> LANL-97A -> 1989-046 The timing is determined by earthward propagating velocity, azimuthal expanding velocity and particle drift velocity. 11:18 THC SST ION ~1min LANL-97A Ion 1989-046 Electron 1989-046 ~4min e- i+ LANL-97A THEMIS-C THD SST ION 2~3min THEMIS-D A B
Pulse field in the model (based on Li et al,1998 and Sarris et al, 2002 models) E_pulse (mv/m) 1989-046 e- B_pulse (nT) 15O p+ LANL-97A THEMIS-C THEMIS DBA r (Re) Snapshots of the pulse
1989-046 LANL-97A THEMIS-C THEMIS-D A B
Comparison between observation and preliminary simulation results Eflux
Limitations in the interpretation of this event • From the model, we can’t distinguish the azimuthal propagation between THEMIS D,B and A due to the time resolution. • The dipolarization seen by THEMIS C was not as clear as it seen by D,B and A. • The injection in lower energy channels (<100 keV) is not clearly seen by THEMIS C in the data.
Summary • Some of the main features of injections are reproduced by this preliminarytest particle simulation. The timing is roughly reproduced as well. • The injections might be explained by one injection process with an earthward propagating pulse at 23 local time. • Detailed simulation will be carried on in future works.