Impact of Sudden Solar Wind Dynamic Pressure Variations on the Geospace System

Sudden solar wind dynamic pressure variations can produce significant global impact on the coupled magnetosphere-ionosphere-thermosphere (MIT) system. In particular, the effects of compression due to sudden pressure increase have been studied extensively using various instruments and numerical models. However, very limited studies have been carried out focusing on ionosphere-thermosphere responses during those dynamic pressure variations and their subsequent impact on technology, such as GNSS receiver performance. In this presentation, I will talk about our recent work on the coupled MIT system responses after sudden solar wind dynamic pressure changes. Multiple ground- and space-based instruments have been used to characterize the current, convection, ionospheric plasma and thermospheric density variations in the polar region after the sudden dynamic pressure changes. In addition, scintillation receivers in both hemispheres have been used to study the scintillation effects due to propagation of pressure-change induced field-aligned currents. Moreover, numerical simulations using the Space Weather Modeling Framework (SWMF), including the BATSRUS MHD model and the GITM model, have also been carried out to quantify the pressure change induced perturbations in the geospace system.