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Ann. Geophys., 25, 881-893, 2007
www.ann-geophys.net/25/881/2007/
© European Geosciences Union 2007
First-principles modeling of geomagnetically induced electromagnetic fields and currents from upstream solar wind to the surface of the Earth
A. Pulkkinen1,2, M. Hesse2, M. Kuznetsova2, and L. Rastätter2,3
1Goddard Earth Sciences and Technology Center, University of Maryland, Baltimore, MD, USA
2NASA/GSFC, Greenbelt, Code 674, MD 20771, USA
3Catholic University, Washington D.C., USA
Abstract. Our capability to model the near-space physical phenomena has gradually
reached a level enabling module-based first-principles modeling of
geomagnetically induced electromagnetic fields and currents from upstream
solar wind to the surface of the Earth. As geomagnetically induced currents
(GIC) pose a real threat to the normal operation of long conductor systems on
the ground, such as high-voltage power transmission systems, it is quite
obvious that success in accurate predictive modeling of the phenomenon would
open entirely new windows for operational space weather products.
Here we introduce a process for obtaining geomagnetically induced
electromagnetic fields and currents from the output of global magnetospheric
MHD codes. We also present metrics that take into account both the complex
nature of the signal and possible forecasting applications of the modeling
process. The modeling process and the metrics are presented with the help of
an actual example space weather event of 24–29 October 2003. Analysis of the
event demonstrates that, despite some significant shortcomings, some central
features of the overall ionospheric current fluctuations associated with GIC
can be captured by the modeling process. More specifically, the basic
spatiotemporal morphology of the modeled and "measured" GIC is quite
similar. Furthermore, the presented user-relevant utility metrics demonstrate
that MHD-based modeling can outperform simple GIC persistence models.
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