Magnetospheric Currents V28

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 28.

When viewed from outer space, the earth's magnetic field does not resemble a simple dipole but is severely distorted into a comet-shaped configuration by the continuous flow of solar wind plasma. A complicated system of currents flows within this distorted magnetic field configuration called the "magnetosphere." For example, the compression of the geomagnetic field by the solar wind plasma on the dayside of the earth is associated with a large-scale current flowing across the geomagnetic field lines, called the Chapman-Ferraro or magnetopause current. The magnetospheric system includes large-scale currents that flow in the "tail," "Birkeland" currents that flow along geomagnetic field lines into and away from the two auroral regions, the ring current that flows at high altitudes around the equator of the earth, and a complex system of currents that flows completely within the layers of the ionosphere, the earth's ionized atmosphere. The intensities of these various currents reach millions of amperes and are closely related to solar activity.