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Small Scale dB/dt Fluctuations: Resolving and Exploring Spikes in Global Models
  • Elizabeth Vandegriff
Elizabeth Vandegriff
University of Texas at Arlington

Corresponding Author:[email protected]

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One of the prominent effects of space weather is the variation of electric currents in the magnetosphere and ionosphere, which give rise to rapid geomagnetic field variations on the surface of the Earth. These Geomagnetic Disturbances (GMDs) can be highly localized and large amplitude. Because the causes of localized GMDs are unresolved, we seek to identify the physical drivers of these localized dB/dt spikes measured by ground magnetometers. We use the Space Weather Modeling Framework (SWMF) models to simulate the magnetosphere and reproduce these small-scale spikes. We use the operational Geospace configuration, which couples a global magnetohydrodynamic model to a height-integrated ionospheric electrodynamics solver and a kinetic ring current model. We run a series of simulations with increasingly higher spatial resolution to resolve small scale dB/dt dynamics. We quantify the success of the model against observation using Regional Station Difference (RSD), a metric calculated using dB/dt or geoelectric field to pinpoint when a single magnetometer station records a significantly different value than others within a given radius. We discuss future work to improve the model’s accuracy and our understanding of these small-scale structures.