Publication Date:
2016-01-20
Description:
Field aligned currents (FACs) play an important role in the coupling between the ionosphere and magnetosphere. Numerical simulation of these phenomena is of increasing interest, but validation has been hampered by a lack of a formal framework to compare simulations to satellite derived products. We develop a statistical approach to comparing FAC simulations from global magnetohydrodynamical models against satellite products. We introduce a robust algorithm that automatically detects and defines region-1 and 2 FACs. In an example, currents derived from the Iridium satellites are compared against simulated currents from two resolutions of the Lyon-Fedder-Mobarry model on one solar event. We assess both average and structured discrepancy, the former being a level shift of the physical model away from the satellite product, while structural discrepancy refers to time-varying, continuous differences. For this event, the lower resolution version of the LFM is shown to be a poor representation of the satellite-derived FACs, while the higher resolution version substantially reduces discrepancy.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
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