Mirror mode structures in the asymmetric Hermean magnetosheath: Hybrid simulations

摘要

abstract_textpResults of two global three-dimensional hybrid simulations of the solar wind interaction with the Hermean magnetosphere are presented for southward and northward interplanetary magnetic field (IMF) orientations. Important dawn-dusk asymmetries of the Hermean bow shock and magnetosheath are observed depending on the IMF orientation. For the southward IMF, the dawnside has a thicker magnetosheath with higher beta values and slower bulk velocities compared to the duskside, whereas for the northward IMF, the duskside has a thicker and higher beta magnetosheath with slower bulk velocities. Mirror mode activity consequently appears at the dawnside for the southward IMF and at the duskside for the northward IMF. A mechanism for the bow shock and magnetosheath asymmetries is proposed and discussed in the context of the Hermean and terrestrial magnetosheaths. Citation: Hercik, D., P. M. Travnicek, J. R. Johnson, E.-H. Kim, and P. Hellinger (2013), Mirror mode structures in the asymmetric Hermean magnetosheath: Hybrid simulations, J. Geophys. Res. Space Physics, 118, 405-417, doi:10.1029/2012JA018083./p/abstract_text