HR: 0800h
AN: SM31B-0461    [Abstracts]
TI: Solar Wind Speed as a Driver of Magnetospheric Activity
AU: * Pulkkinen, T I
EM: Tuija.Pulkkinen@fmi.fi
AF: Finnish Meteorological Institute, POBox 503, Helsinki, FI-00101, Finland
AU: Partamies, N
EM: noora.partamies@fmi.fi
AF: Finnish Meteorological Institute, POBox 503, Helsinki, FI-00101, Finland
AU: Palmroth, M
EM: minna.palmroth@fmi.fi
AF: Finnish Meteorological Institute, POBox 503, Helsinki, FI-00101, Finland
AU: McPherron, R L
EM: rmcpherro@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, 6711 Geology, Los Angeles, CA 90095-1567, United States
AU: Goodrich, C C
EM: ccg@bu.edu
AF: Center for Space Physics, Boston University, 725 Commonwealth Avenue, Boston, MA 02215, United States
AB: Statistical analysis of sawtooth events and steady magnetospheric convection (SMC) periods show that the solar wind speed is much higher during sawtooth events than it is during SMC periods even for a set of cases with similar driving solar wind electric field values. Thus, high solar wind speed seems to induce periodic activity while low speed and larger IMF tend to produce a steadily convecting, rather stable magnetosphere. Further statistics of all activity conditions shows that during southward IMF, for the same solar wind electric field value larger speed and smaller Bz magnitude drive higher activity than smaller speed and larger Bz magnitude. These results are confirmed by results from three LFM global MHD simulation runs, which show that originally stable magnetosphere remains stable if IMF Bz magnitude is increased, while stronger activity and localized flows appear if the solar wind speed is increased. All these results point out the key role of the solar wind speed in determining the global state of the magnetosphere.
DE: 2740 Magnetospheric configuration and dynamics
DE: 2753 Numerical modeling
DE: 2784 Solar wind/magnetosphere interactions
DE: 2788 Magnetic storms and substorms (7954)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting