Solar wind streamer belt structure

Abstract

In the course of 2 days in October 1978, ISEE 3 encountered 14 magnetic field reversals, five pronounced and several lesser high‐beta regions called “plasma sheets,” two distinct entropy regimes, two heat flux dropouts (HFDs), and planar magnetic structure led by a shock wave. The complexity of the interval afforded an excellent opportunity to determine the relationships between these streamer belt structures, their geometry and topology, and the resulting implications for the structure of the heliospheric current sheet (HCS). None of the results of three tests applied to the data support a wavy or folded HCS hypothesis. In particular, a test for true magnetic polarity using primarily heat flux data indicated that the field reversals occurred in a predominantly toward sector with three pockets of true away polarity and three of false away polarity. The results are consistent with a view in which current sheets bound intertwined flux ropes, some of which coil back on themselves, possibly as remnants of transient coronal activity. A comparison between joint occurrences of the various structures showed that the most intense plasma sheets in the interval coincided with true polarity reversals, that nearly every reversal, whether true or false, corresponded to at least a weak plasma sheet, and that plasma sheets occurred within HFD intervals. The plasma sheet/HFD relationship was statistically confirmed in a search for plasma sheets in published HFDs.