The Orientation of Plasma Structure in the Solar Wind

. Data from the ISEE 3# IMP 8# and WIND spacecraft are used to #nd the average east#west orientation of plasma structures in the solar wind. We determine the lags which# after radial propagation e#ects are removed# give the best correlations between data sets. These lags# when combined with the spacecraft positions and solar wind speeds# are then used to calculate the front angles of the propagating plasma. The average front normals are neither radial nor perpendicular to the magnetic #eld# but are roughly halfwaybetween. Front angle distributions peak at lower angles near solar maximum than at solar minimum. These results may indicate that time#dependentchanges in the solar wind source are as important as longitudinal variations of the source in producing the solar wind structure observed near Earth. 1. Introduction The interplanetary magnetic #eld #IMF# direction at Earth is determined by the Sun#s rotation# the speed of the solar wind which carries the #eld outward# stream interac..

Solar Wind Correlations: Using A Solar Wind Monitor Successfully

Solar wind plasma correlations between data from three spacecraft -- IMP 8, INTERBALL-1, and WIND -- are analyzed for periods near the most recent solar minimum. There are two primary foci of this study: 1) to understand the physics underlying good and poor correlation periods, and 2) to investigate and quantify the degree to which distant solar wind plasma measurements (such as those from near Earth's L1 point) represent the solar wind affecting the magnetosheath and magnetosphere

IMP 8 observations of a poleward plasma circulation Evidence of entry into the plasma mantle

. Plasma data from IMP 8 are used to map the spatial structure of plasma #ow in Earth#s magnetosheath. Plasma and magnetic #eld data from instruments on ISEE#3 and WIND are used to normalize the IMP 8 magnetosheath data to upstream solar wind conditions. For the majority of the data# the magnitude and direction of plasma #ow inside the magnetosheath agree well with gas#dynamic models. About 8# of the ISEE#3#normalized velocityvectors and 3# of the WIND#normalized velocity vectors exhibit a poleward circulation in the YZ plane. The observed circulation is consistent with predictions for #ow within the plasma mantle. The occurrence frequency of these poleward #ows increases further down the tail# consistent with predictions that the mantle width increases tailward. Densities are lower where this #ow is observed# consistent with expectations for the plasma mantle# but temperatures are higher and the magnetic #eld magnitudes lower# the opposite of theoretical expectations. 3 Introductio..