Geosynchronous magnetic field responses to fast solar wind dynamic pressure enhancements: MHD field model
We performed global MHD simulations of the geosynchronous magnetic field in response to fast solar wind dynamic pressure ( Pd) enhancements. Taking three Pd enhancement events in 2000 as examples, we found that the main features of the total field B and the dominant component Bz can be efficiently predicted by the MHD model. The predicted B and Bz varies with local time, with the highest level near noon and a slightly lower level around mid-night. However, it is more challenging to accurately predict the responses of the smaller component at the geosynchronous orbit (i.e., Bx and By). In contrast, the limitations of T01 model in predicting responses to fast Pd enhancements are presented.