Events Calendar

From Global Simulations to Local Auroras: Multi-scale Approach to Magnetosphere-Ionosphere Coupling

Shannon Hill, PhD; Climate and Space Sciences and Engineering, University of Michigan

We explore the multi-scale processes of magnetosphere-ionosphere coupling with the use of satellite observations, ground-based observations, and global simulations in four separate research studies. At the smallest scale, we use satellite observations to study magnetosonic wave heating of thermal ions in the inner magnetosphere. Next, we expand to the mesoscale and include the ionosphere through wave-particle scattering. We use satellite and ground-based observations to study the correlation between chorus wave activity in the inner magnetosphere and pulsating aurora in the ionosphere. Then, we analyze large-scale coupling with satellite observations and global simulations to study impacts of magnetotail dynamics on the ionosphere. We simulate theta aurora observations to explore magnetotail configurations that can produce high intensity precipitation in the polar cap regions of the ionosphere. We end our exploration at the largest scale: global magnetosphere-ionosphere coupling. We continue with theta aurora simulations to investigate global magnetosphere-ionosphere coupling during periods of northward IMF. The simulation produces two reversed ionospheric convection cells in a nearly closed polar cap. We investigate global magnetosphere merging configurations that could produce ionospheric convection reversal during theta aurora events. We use the four research studies discussed in this talk to show that we must incorporate the multiple scales of magnetosphere-ionosphere coupling to accurately describe the evolution of the magnetosphere-ionosphere system. The plasma physics on small scales is complicated and can be computationally expensive to model, yet the use of global simulations to force the system to an outcome consistent with external forces can oversimplify the wave-particle interactions important to magnetosphere-ionosphere coupling. The best approach to understanding the magnetosphere-ionosphere coupling system is a creative use of different research techniques with varied data sets that combines the satellite and ground-based observations with global simulations.