Magnetopause stand-o distance in dependence on the magnetosheath and solar wind parameters

A model of the magnetosheath structure proposed in a recent paper from the authors is extended to estimate the magnetopause stand-o€ distance from solar wind data. For this purpose, the relationship of the magnetopause location to the magnetosheath and solar wind parameters is studied. It is shown that magnetopause erosion may be explained in terms of the magnetosheath magnetic ®eld penetration into the magnetosphere. The coecient of penetration (the ratio of the magnetospheric magnetic ®eld depression to the intensity of the magnetosheath magnetic ®eld Bm?z ˆ ÿBm sin H=2, is estimated and found approximately to equal 1. It is shown that having combined a magnetosheath model presented in an earlier paper and the magnetosheath ®eld penetration model presented in this paper, it is possible to predict the magnetopause stand-o€ distance from solar wind parameters.