HR: 09:30h
AN: SH51D-06    [Abstracts]
TI: CME's low Mach number leads to a low Beta magnetosheath which alters their interaction with the magnetosphere
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: * 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
AB: In this paper we illustrate some expectations for the interaction between low Mach number solar wind (often characteristic of CMEs) and the magnetosphere. A result of the low (Alfven) Mach number solar wind is the formation of a low thermal beta magnetosheath downstream of the Earth's bow shock. Because of such properties, magnetic forces become prominent and largely rule the properties of the magnetosheath flow and of its coupling with the magnetosphere. We first illustrate such effects by use of spacecraft data (a case when Cluster was adequately located in the magnetosehath) and MHD simulations for such a low Mach number solar wind case. We generally predict (a) high-velocity flow jets in the magnetosheath adjacent to the magnetopause, (b) reduced flows in other regions of the magnetosheath, (c) asymmetric shapes for the magnetopause, and (d) anomalous magnetic-field stretching of the dipolar portions of the magnetosphere, which we relate to the occurrence of sawtooth events.
DE: 2101 Coronal mass ejections (7513)
DE: 2111 Ejecta, driver gases, and magnetic clouds
DE: 2724 Magnetopause and boundary layers
DE: 2728 Magnetosheath
DE: 2740 Magnetospheric configuration and dynamics
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Joint Assembly