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Ann. Geophys., 25, 1345-1358, 2007
www.ann-geophys.net/25/1345/2007/
© European Geosciences Union 2007
A global MHD simulation of an event with a quasi-steady northward IMF component
V. G. Merkin1, J. G. Lyon2, B. J. Anderson3, H. Korth3, C. C. Goodrich1, and K. Papadopoulos4
1Center for Space Physics, Boston University, Boston, MA, USA
2Department of Physics and Astronomy, Dartmouth College, Hanover, NH, USA
3The Johns Hopkins University, Applied Physics Laboratory, Laurel, MD, USA
4Department of Astronomy, University of Maryland, College Park, MD, USA
Abstract. We show results of the Lyon-Fedder-Mobarry (LFM) global MHD
simulations of an event previously examined using Iridium spacecraft
observations as well as DMSP and IMAGE FUV data. The event is chosen
for the steady northward IMF sustained over a three-hour period
during 16 July 2000. The Iridium observations showed very weak or
absent Region 2 currents in the ionosphere, which makes the event
favorable for global MHD modeling. Here we are interested in
examining the model's performace during weak magnetospheric forcing,
in particular, its ability to reproduce gross signatures of the
ionospheric currents and convection pattern and energy deposition in
the ionosphere both due to the Poynting flux and particle
precipitation. We compare the ionospheric field-aligned current and
electric potential patterns with those recovered from Iridium and
DMSP observations, respectively. In addition, DMSP magnetometer data
are used for comparisons of ionospheric magnetic perturbations. The
electromagnetic energy flux is compared with Iridium-inferred
values, while IMAGE FUV observations are utilized to verify the
simulated particle energy flux.
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