HR: 11:05h
AN: SM22A-04    [Abstracts]
TI: Cold, Dense Plasma Access to Geosynchronous Orbit and its Relation With Geomagnetic Activity
AU: * Lavraud, B
EM: lavraud@lanl.gov
AF: Los Alamos National Laboratory, Space Science and Applications P.O. Box 1663, MS D466, Los Alamos, NM 87545 United States
AU: Denton, M H
EM: mhdenton@lanl.gov
AF: Los Alamos National Laboratory, Space Science and Applications P.O. Box 1663, MS D466, Los Alamos, NM 87545 United States
AU: Thomsen, M F
EM: mthomsen@lanl.gov
AF: Los Alamos National Laboratory, Space Science and Applications P.O. Box 1663, MS D466, Los Alamos, NM 87545 United States
AU: Borovsky, J E
EM: jborovsky@lanl.gov
AF: Los Alamos National Laboratory, Space Science and Applications P.O. Box 1663, MS D466, Los Alamos, NM 87545 United States
AU: Friedel, R H
EM: rfriedel@lanl.gov
AF: Los Alamos National Laboratory, Space Science and Applications P.O. Box 1663, MS D466, Los Alamos, NM 87545 United States
AU: Seki, K
EM: seki@stelab.nagoya-u.ac.jp
AF: Solar-Terrestrial Environment Laboratory, Nagoya University, Honohara 3-13, Toyokawa, Aichi, 442-8507 Japan
AU: Weygand, J
EM: jweygand@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, Department of Earth and Space Sciences, 3845 Slichter Hall, P.O. Box 951567, Los Angeles, CA 90095 United States
AB: We present a superposed epoch analysis of 697 events of cold (Ti < 5 keV) and dense (Ni > 2/cc) plasma observed by the MPA instruments onboard the Los Alamos geosynchronous satellites, for the period 1990-2002. The results allow us to study the temporal evolution of various plasma parameters as a function of local time. We show that cold, dense plasma access to geosynchronous orbit occurs both near local midnight and dawn. The dense plasma population observed near local midnight is shown to be freshly injected from the mid-tail region, colder than the typical plasma sheet and composed of a relatively small O+ component. This population is thus probably the result of cold, dense plasma sheet (CDPS) injection from the mid-tail region. We further investigate and discuss its differences with the population observed at the dawn side of geosynchronous. These two populations in particular appear to be correlated with different external (IMF and ram pressure) and internal (Kp and Dst) parameters.
DE: 2760 Plasma convection (2463)
DE: 2764 Plasma sheet
DE: 2778 Ring current
DE: 2784 Solar wind/magnetosphere interactions
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005