ICS-6 Short Abstracts

Abstract Profile:

Paper#: 153

Poster #:

Session Name: Workshop 3B: M/I Coupling

Room: West Ballroom

Day: Tuesday

Time: 4:55-5:15 p.m.

Abstract Title: CLUSTER Observations of the CPS and the PSBL Tailward of and Close to the Reconnection Site

PresentSurname: Mouikis, C.

All Authors: C. Mouikis, L.M. Kistler, B. Klecker, J.-A. Sauvaud, M. Dunlop

Abstract : We present multi-spacecraft observations of the Central Plasma Sheet (CPS) and the Plasma Sheet Boundary Layer (PSBL) as observed by the CIS-CODIF instrument on CLUSTER during the main phase of the August 17, 2001 storm. The CLUSTER S/C were at apogee (~20 Re) in the midnight region (~0100 MLT). The CIS-CODIF instrument measured ion distribution functions of the major species, H+, He++, He+ and O+ over the energy range 20 eV - 40 keV. During this event CLUSTER is probing the CPS and the PSBL with the S/C being situated tailward of the reconnection region after reconnection takes place. Before reconnection, the CPS is dominated by field aligned bi-directional H+ and O+ beams while in the PSBL earthward field aligned H+ flows are observed. After reconnection and the plasmoid ejection (that results in a very depleted CPS), the plasma sheet is very dynamic and the Z component of the magnetic field fluctuates between near zero and negative values. High velocity (~700 km/s) tailward convective flows are observed in the CPS. In the PSBL high velocity (~1,500 km/s) tailward field aligned H+ flows are present while at times a flow reversal is observed. Due to the very thin current sheet, the CLUSTER S/C probe the region between the CPS and the PSBL simultaneously providing a unique opportunity to study this very dynamic environment.