Modeling Interchange Instabilities in the Ionosphere with a Fully Electromagnetic MHD Solver

We present an updated Magnetohydrodynamic (MHD) solver, derived from the PERSEUS code, to simulate electromagnetic effects from plasma instabilities in the ionosphere. The solver incorporates the finite volume method alongside a range of numerical techniques, including Total Variation Diminishing, the Rusanov scheme for flux computation, and a relaxation method. While specifically designed to capture interchange instabilities, the solver is fully electromagnetic and applicable to a broader range of ionospheric instabilities. This solver can recover phenomena occurring on short timescales (~milliseconds) while maintaining scalability for large-scale simulations (~100 km) over long timescales (hours to days) within feasible computational limits. This code will support the interpretation of measurements from NASA’s upcoming rocket campaign in Peru in 2028.