How does the Ionosphere Drive the Magnetospheric Processes?

Solar wind – magnetosphere – ionosphere interactions are often interpreted as the solar wind flow and interplanetary magnetic field driving the dynamic processes in the magnetosphere – ionosphere system. However, the atmosphere and the ionosphere host independent dynamic processes, which also influence the magnetospheric dynamics in as yet unquantified ways. In this study, we assess the ability of the global MHD simulations to predict geomagnetic indices, and the role the ionospheric conductance plays in the magnetosphere – ionosphere coupling processes. Specifically, we use the University of Michigan Space Weather Modeling Framework and its Geospace configuration in two different setups: one using the standard Ridley Ionosphere Model (setup similar to that operationally used by the NOAA Space Weather Prediction Center) and another using the  Conductance Model for Extreme Events (CMEE). Comparing the model results for subsolar magnetopause position, AL, Dst, and cross-polar cap potential (CPCP) indices with observed quantities allows us to assess the role of the ionospheric conductance model as well as the overall level of uncertainty within the model as function of the driving intensity. The comparisons are done using a large set of over 80 simulations of geomagnetic storms using both setups.