Spiral, Warped Current Sheet

Spiral, Warped Current Sheet

. Near the minimum in the Sunís 11-year activity cycle, the Sunís magnetic field is primarily directed outward from one pole and inward in the other. The oppositely directed magnetic field lines meet near the solar equator, forming a thin, wave-like neutral current sheet that divides magnetic fields directed away from the Sun and those directed toward it. The neutral current sheet winds out above the Sunís equator, with a spiral shape and a warped structure that resembles the skirt of a ballerina or a whirling dervish. As it rotates with the Sun, the current sheet sweeps regions of opposite magnetic polarity past the Earth. (Courtesy of J. Randy Jokipii, and the Advanced Composition Explorer mission).

Copyright 2010, Professor Kenneth R. Lang, Tufts University