Invariant magnetic shells in the earth field distorted by solar wind

Abstract

Invariant magnetic shells in the Earth field distorted by the solar wind. The closed invariant surfaces along which particles are trapped in the solar wind distorted field, in quiet times, are studied using the Williams and Mead "open field model". The shell coordinates (I, Bm), and the daily latitudinal shift of mirror points along noon and midnight field lines are computed; the night decrease of the equatorial pitch angle of a trapped particle is shown. The daily variation of I and L, and the inadequacy of the L parameter for points within the distorted region of the magnetosphere are considered. The spacial spreading of the shells of particles injected under different pitch angles along distorted field lines is discussed. The region within the cavity where, due to the compression of day lines and the elongation and opening of night lines no stable trapping occurs. is described.