Three dimensional shape of the magnetopause: Global MHD results

Abstract

[1] The numerical results from a physics‐based global magnetohydrodynamic (MHD) model are used to examine the relationship between the shape and size of the magnetopause and the solar wind conditions. The magnetopause location is identified by tracing three‐dimensional streamlines through the simulation domain and is fitted by simple analytical functions. The resulting model is applicable for approximating magnetopause location for dipole tilt angle ∼0° and interplanetary magnetic field (IMF) BX and BY = 0 nT at both low and high magnetospheric latitudes. In both regions the results are compared with available empirical models. It is shown that IMF BZ mainly affects the flaring angle (the magnetopause shape) and has smaller effects on the magnetopause size. In contrast, the solar wind DP mainly affects the magnetopause standoff distance (magnetopause size) and has little effect on the magnetopause shape. Both conclusions are consistent with empirical models.