Solar wind and location of shock front and magnetopause at the 1969 solar maximum

Abstract

A general survey of the average properties of interplanetary plasma from December 11, 1968, to April 13, 1969, and from August 27, 1969, to January 10, 1970, is presented, as observed by the European satellite Heos 1. The average values of the proton parameters are: number density, 4.3 p/cm³; bulk velocity, 409 km/sec; and most probable thermal speed, 33 km/sec. A map is presented of the observed magnetosheath traversals. A parabolic best fit of bow shock and magnetopause crossings gives, at the subsolar point, distances of 15.2 and 12.4 RE from the earth, respectively. The average plasma parameters and the positions of the discontinuity surfaces are compared with the results obtained by other satellites and space probes during the last period of low solar activity.