HR: 1340h
AN: SM13B-1207    [Abstracts]
TI: Observations of Cold Dense Plasma Sheet and Cusp Reconnection During Extended Periods of Northward IMF
AU: * Oieroset, M
EM: oieroset@ssl.berkeley.edu
AF: Space Sciences Laboratory, University of California, Berkeley, CA 94720 United States
AU: Phan, T D
EM: phan@ssl.berkeley.edu
AF: Space Sciences Laboratory, University of California, Berkeley, CA 94720 United States
AU: Raeder, J
EM: J.Raeder@unh.edu
AF: Department of Physics, University of New Hampshire, Durham, NH 03824-3525 United States
AU: Fujimoto, M
EM: fujimoto@geo.titech.ac.jp
AF: Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo, 152-8551 Japan
AU: Wing, S
EM: Simon.Wing@jhuapl.edu
AF: Applied Physics Laboratory, Johns Hopkins University 11100 Johns Hopkins Rd, Laurel, MD 20723-6099 United States
AU: McFadden, J P
EM: mcfadden@ssl.berkeley.edu
AF: Space Sciences Laboratory, University of California, Berkeley, CA 94720 United States
AU: Reme, H
EM: henri.reme@cesr.fr
AF: CESR, BP4346, Toulouse Cedex 4, 31028 France
AU: Balogh, A
EM: a.balogh@imperial.ac.uk
AF: Space and Atmospheric Physics Group, Imperial College , London, SW7 2BZ United Kingdom
AB: During the October 22-25, 2003 interval strong solar activity resulted in several intervals of long duration strongly northward IMF. Using observations from Cluster, Geotail, DMSP, and FAST we investigate the state of the magnetosphere during these extreme solar wind conditions. We find that long duration strongly northward IMF results in global cooling ($<1$ keV) and densification ($\sim$1 cm$^{-3}$) of the entire plasmasheet, at all local times, and at all latitudes, including the neutral sheet. The transition to cold and dense plasma sheet occurs gradually over 3-4 hours following the northward turning of the IMF and the cold dense plasma starts to disappear when the IMF becomes $B_y$ dominated. During the cold dense plasma sheet intervals the FAST satellite observed inverse ion dispersion signatures in the cusp indicative of poleward-of-cusp reconnection, and nearly no polar cap. The observations show good quantitative agreement with global MHD simulations where the CDPS is formed by poleward-of-cusp reconnection capturing magnetosheath plasma which convects to the tail. The size of the lobes also shrank significantly in the simulation due to cusp reconnection.
DE: 7835 Magnetic reconnection
DE: 2731 Magnetosphere--outer
DE: 2740 Magnetospheric configuration and dynamics
DE: 2744 Magnetotail
DE: 2764 Plasma sheet
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting