High-Fidelity Discontinuous Galerkin Method for Physics-Based Space Weather Modeling

Abstract

Physics-based models of the ionosphere–thermosphere system have been devised as a necessary tool to predict atmospheric outputs for different space applications. For example, for obtaining reliable predictions of atmospheric drag for low-Earth orbiting satellites or forecasting purposes of extreme space weather events. To this end, this study proposes a high-fidelity approach for physics-based space weather modeling based on the discontinuous Galerkin (DG) method. The proposed model describes an atmosphere in non-hydrostatic equilibrium driven by the extreme ultraviolet (EUV) radiation from the Sun. The multiscale variations in the radial and angular directions are managed in a non-segregated strategy, employing a proper scaling of the momentum and energy variables. On the other hand, the logarithm of the density is introduced as the primary quantity to deal with the low densities present in the upper atmosphere. The numerical scheme combines a matrix-free approach suitable for high-performance computing on graphic processors (GPUs). A numerical example reproducing solar equinox conditions is presented in this work to validate the proposed methodology.