Rotational Influence on the Martian Magnetotail Current Sheet: A Multispecies MHD Study

Abstract The Martian magnetotail current sheet exhibits a dawn‐dusk asymmetry, but the reasons for this shift remain unclear. Although crustal magnetic fields influence this asymmetry, most magnetohydrodynamic (MHD) simulations focus on the subsolar orientation of 180°W, 0°N, which places the strongest crustal fields on the dayside and overlooks potential longitudinal variability. This study employs the BATS‐R‐US multispecies MHD code to simulate the solar wind interaction with Mars at various subsolar longitudes, aiming to evaluate how the orientation of crustal magnetic fields shapes the structure of the magnetotail. The results show that the crustal field orientation controls whether the current sheet shifts dawnward, duskward, or alternates between the two regions. Current density analysis reveals that the current sheet is bifurcated (two spatially distinct current channels) from 0°W to 195°W and uniform from 210°W to 345°W. Analysis of the mass flux shows that it aligns with the bifurcation/uniformity of the current density, showing where plasma escapes through the magnetotail. The study demonstrates that crustal field orientation is a key factor in shaping the Martian magnetotail structure.