GEM: A Parametric Study of Geomagnetic Storms during Magnetic Cloud Intervals Using Global MHD Simulations

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The goal of this project is to expand our understanding of the effects of various magnetic cloud configuration on the magnetosphere - ionosphere system by analyzing simulations for a set of idealized magnetic clouds occur in variety of different configurations. The polarity of the magnetic field orientation appears to be ordered by solar cycle and may have a determining role on the geoeffectiveness of a given magnetic cloud. Furthermore, magnetic clouds are often accompanied by interplanetary shocks, high-speed streams and trailing density enhancements. The development of an understanding of fundamental physics involved in these interactions has been hampered by an inability to separate these potentially synergistic features. The Lyon-Fedder-Mobarry (LFM) global MHD code will be used to simulate the magnetosphere - ionosphere system under a variety of magnetic cloud conditions. In addition, a 2-D relativistic guiding center particle code will be used to mode the evolution of the radiation belts. The study will focus on 1) varying the polarity of the magnetic cloud, 2) changing the duration of the IMF rotation interval, 3) changing the energy input into the magnetosphere, and 4) including trailing density enhancements. A baseline set of parameters derived from the simulation will be used to assess which features control the geoeffectiveness of a given configuration.