Two-Way SWMF-GITM Coupling for Space Weather Applications

The neutral thermosphere is a crucial component of the space weather system, both directly and indirectly. As energy is deposited into the thermosphere through precipitation and Joule heating, the neutral scale height increases, and low Earth orbiting spacecraft experience increased drag. Neutral densities also set conditions for the development of ionospheric conductivity, changing current closure through the upper atmosphere. As such, the strength and location of electrojets are a function of both solar driving and thermospheric conditions. This alters energy flow through the magnetosphere-ionosphere-thermosphere system and changes the regions most at risk for GIC and other phenomena.

In this presentation, we outline efforts to include the thermosphere in global simulations by coupling the Global Ionosphere Thermosphere Model, GITM, to the Space Weather Modeling Framework (SWMF). We simulate several contemporary severe events, including the Sept. 2017 and May 2024 “Gannon” storms. Results are compared and contrasted to simulations with no thermosphere to examine how neutral dynamics change space weather impacts. Operationally-relevant values are inspected, including ground magnetic disturbances and neutral densities at LEO orbits. This work is part of the SWORD NASA DRIVE Center and the Solar Tsunamis project.