Origin of the Radial Interplanetary Magnetic Field and Its Interactions With the Magnetosphere

Abstract:

The interplanetary magnetic field (IMF) is usually aligned with a spiral form because of the solar rotation. For some cases, this orientation becomes radial, i.e., the solar wind is flowing in the same direction as the orientation of the IMF. Under such a circumstance, the magnetospheric system, including the bow shock, the magnetosheath, the magnetopause, and the magnetosphere, responds to the radial IMF in ways that are 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, local active field-aligned currents can be observed in the high-latitude ionosphere. In this presentation, the current understandings and future perspectives in origin of the radial IMF and its interactions with the magnetosphere will be reviewed.