Comparison between Global MHD Simulations and IMAGE Observations

Berchem, J.

With its ability of imaging the global magnetosphere, the IMAGE mission
provides a unique opportunity to test the progress of the global modeling
of the solar wind interaction with the Earth's magnetosphere. In
particular, IMAGE observations of the dayside auroral activity allow
investigating the response of the Earth's magnetosphere to interplanetary
disturbances. Modeling the effects of such transient disturbances is an
important step toward understanding the complex dynamics of geomagnetic
storms. In this talk, we compare IMAGE auroral observations with the
results from three-dimensional magnetohydro-dynamic (MHD) simulations.
The study focuses on the investigation of the interaction of
interplanetary shocks and strong pressure pulses with the magnetosphere,
and its main objectives are to identify and understand the large-scale
dynamics of the magnetopause boundary and the intensification of the
dayside auroral activity observed on the arrival of interplanetary
disturbances. To achieve these goals we have modeled several events using
plasma and magnetic field parameters measured upstream of the bow shock
as input to the simulations. We compare and discuss the IMAGE
observations of the events in the context of the dayside magnetosphere's
topological changes in magnetic field and plasma flows inferred from the
simulation results.

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To be presented at the Magnetospheric Imaging Workshop, 
Yosemite National Park, California, U.S.A., Feb. 5-8, 2002.