Draping of strongly flow-aligned interplanetary magnetic field about the magnetopause

Abstract

Many dynamic processes of the magnetosphere are directly driven by the solar wind and the occurrence of magnetic merging at the magnetopause. The location of magnetopause magnetic merging, or reconnection, is now fairly well understood when the interplanetary magnetic field (IMF) contains large By and Bz components in relation to the Bx component (in Geocentric Solar Magnetospheric (GSM) coordinates). However, when the IMF contains a large X-component (i.e., is closely flow-aligned), it is not yet well understood how the shocked IMF drapes about the magnetopause, and how this affects the occurrence and location of magnetic merging. In this initial study, we examine from observations how a nearly flow-aligned IMF drapes about the magnetopause. The results of this study are expected to be useful for comparisons with both analytic and global numerical models of the magnetosheath magnetic field.