Dissecting Earth's Magnetosphere: 3D Energy Transport in a Simulation of a Real Storm Event

Abstract

We present new analysis methods of 3D MHD output data from the Space Weather Modeling Framework during a simulated storm event. Earth's magnetosphere is identified in the simulation domain and divided based on magnetic topology and the bounding magnetopause definition. Volume energy contents and surface energy fluxes are analyzed for each subregion to track the energy transport in the system as the driving solar wind conditions change. Two energy pathways are revealed, one external and one internal. The external pathway between the magnetosheath and magnetosphere has magnetic energy flux entering the lobes and escaping through the closed field region and is consistent with previous work and theory. The internal pathway, which has never been studied in this manner, reveals magnetically dominated energy recirculating between open and closed field lines. The energy enters the lobes across the dayside magnetospheric cusps and escapes the lobes through the nightside plasmasheet boundary layer. This internal circulation directly controls the energy content in the lobes and the partitioning of the total energy between lobes and closed field line regions. Qualitative analysis of four‐field junction neighborhoods indicate the internal circulation pathway is controlled via the reconnection X‐line(s), and by extension, the interplanetary magnetic field orientation. These results allow us to make clear and quantifiable arguments about the energy dynamics of Earth's magnetosphere, and the role of the lobes as an expandable reservoir that cannot retain energy for long periods of time but can grow and shrink in energy content due to mismatch between incoming and outgoing energy flux.

Comparison of Solar Wind Interaction with Mars and Earth: Energy Transfer

“…The calculation of energy through the MPB is similar to that through Earth's magnetopause (Palmroth et al 2003;Lu et al 2013;Brenner et al 2023;Zhang et al 2023b). In order to calculate the mechanical energy and electromagnetic energy of the entire MPB, the entire surface is divided into numerous triangular surface elements composed of three mesh points on the MPB, and the energy flux of the mechanical and electromagnetic energy on each element is calculated respectively as…”