High time resolution observations of the solar wind and backstreaming ions in the Earth’s foreshock region

Abstract

The interaction of the solar wind with ions backstreaming from the earth’s bow shock is studied at high time resolution. It turns out that the bulk velocity of the solar wind oscillates, both in magnitude and direction, with typical periods of ∼1 minute in presence of the ‘diffuse’ ion population. Oscillations of comparable periods are also observed in the angular distribution and energy spectrum of the diffuse ions.