Presentation #125.40 in the session General Topics: Solar — Poster Session.
The high-latitude ionosphere is a dynamic environment influenced not only by magnetospheric precipitation and currents from above but thermospheric motions such as waves, tides, and neutral upwelling from below. All of these external processes, as well as the ion production, loss and transport from within, act together to determine the ionospheric state (viz. local density, momentum, and temperature) and play a critical role in determining the local conductivity.
For the work presented here, the Space Weather Modeling Framework (SWMF) has been updated to include 2-way coupling between the upper atmosphere module (GITM) and the ionospheric electrodynamics module (RIM). This allows for the physics-based calculation of conductance from GITM to be used by RIM for the determination of the electric potential which is passed out to the magnetospheric components (BATS-R-US and RCM). This conductance includes atmospheric effects and directly impacts how magnetospheric currents are closed through the high-latitude ionosphere. It has the ability to affect not only magnetospheric tail dynamics but the whole magnetosphere-ionosphere-thermosphere (MIT) system.
Focusing on the 2015 St. Patrick’s Day storm, the consequences of using the new physics-based conductance formulation vs. the classic empirical formulation are discussed. Model-data comparisons are presented that illustrate the impacts of using the physics-based ionospheric conductivity during pre-storm and storm conditions.