Predicting Thermospheric Density at High Latitude during Magnetic Storms using Coupled Global Geospace Simulations

Accurate prediction of Earth’s thermospheric mass density is important from the perspectives of both space weather prediction and scientific research. Among the various approaches to thermospheric density modeling and forecasting, the use of physics-based, fully coupled global geospace models is probably the most challenging to implement, but it also holds the most promise for possibly accurate specification. In this study, we use the coupled-magnetosphere-ionosphere-thermosphere model to investigate the evolutions of high-latitude thermospheric mass density during magnetic storms. Various physical processes that affect the energy input from the magnetosphere to ionosphere-thermosphere system are studied using high-resolution, coupled global simulations, including localized electromagnetic energy deposition, direct-entry cusp particle precipitation, broadband electron precipitation, ring current, ion outflow. The ability of predicting polar cap thermospheric density during magnetic storms using global geospace models are estimated through event-based data-model comparisons (CHAMP/GRACE). These comparison studies are also used to investigate the relative importantce of various physical processes that relate to the coupling between the magnetosphere and high-latitude ionosphere-thermosphere.