HR: 1340h
AN: SM23A-1196    [Abstracts]
TI: Complexities of a 3-D flux rope as shown by MHD simulation
AU: * Farr, N
AF: University of Colorado - LASP, 1234 Innovation Drive, Boulder, CO 80303, United States
AU: Baker, D N
AF: University of Colorado - LASP, 1234 Innovation Drive, Boulder, CO 80303, United States
AU: Wiltberger, M
AF: NCAR - HAO, 3450 Mitchel Lane, Boulder, CO 80301,
AB: This paper presents the results of a global magnetohydrodynamic (MHD) simulation of a pair of substorms on August 11, 2002. Comparisons of data with simulation results reveal an agreement regarding the sequence of events in the magnetosphere. We then present the results in the simulation of a flux rope formed during the second substorm. Unlike standard 2-D depictions of reconnection and plasmoid release during a substorm, the simulation shows a highly complex structure that has considerable winding of both closed and open field lines. Additionally the flux rope does not move tailward uniformly, but rather has a assymetric motion where the dawn flank moves tailward prior to the dusk end of the flux rope, resulting in a a skewed flux rope that runs almost downtail instead of crosstail. These features can add considerably complexity to satellites observing a flux rope structure in-situ. A single spacecraft could observe particle populations that go through a sequence of alternating open and closed field lines and spacecraft separated by small spatial distances could observe quite different populations as well.
DE: 7835 Magnetic reconnection (2723, 7526)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting