Year: 2025
Type: article
Abstract: Previous studies suggested that Mercury's magnetosphere could possess Earth‐like field‐aligned currents (FACs) despite the absence of an ionosphere. However, due to the limited coverage of spacecraft observations, our understanding of Mercury's FACs is scarce. Here, we employed Amitis, a hybrid‐kinetic plasma model, to investigate the establishment and global pattern of Mercury's FACs. The responses of Mercury's FACs to various interior conductivity profiles and different orientations of the upstream interplanetary magnetic field (IMF) were simulated. It has been shown that the profile of a less resistive upper layer and a conducting core favors the establishment of FACs. Three types of large‐scale FACs (Region 1‐like, Region 2‐like and NBZ‐like FACs) are shown in simulations. Comparison with previous observations suggests that Mercury's effective conductance for closing R1‐like FACs is ∼2.4–3.4 S. The influence of IMF orientation on FACs is similar to that observed in Earth's magnetosphere, but the response of the R2‐like FACs to the IMF orientation is different.
DOI: 10.1029/2024je008610
Institutions: Chinese Academy of Sciences, Institute of Geology and Geophysics, University of Chinese Academy of Sciences, Umeå University, Boston University, Fudan University, Shanghai Institute for Mathematics and Interdisciplinary Sciences, University of Michigan, Swedish Institute of Space Physics
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,070
OpenAlex ID: W4407857317