Origin of the Radial Interplanetary Magnetic Field and Its Effects on the Magnetospheric System

Abstract:

The orientation of the interplanetary magnetic field (IMF) is usually aligned with a spiral form. Sometimes this orientation becomes radial, i.e., the solar wind plasma flowing in align with the IMF. Under this circumstance, the magnetospheric system, including the bow shock, magnetosheath, magnetopause, and magnetosphere, responds to the radial IMF in a way that is different from the other orientations. For example, the magnetopause moves outward and the bow shock moves inward, resulting a thin magnetosheath. Although the magnetospheric state for radial IMF is generally quiet, active local field-aligned currents can be observed in the high-latitude ionosphere. In this presentation, the current understandings and future perspectives on the origin of the radial IMF and its effects on the magnetospheric system will be reviewed.