Plasma waves in slow-mode shocks observed by geotail spacecraft

Abstract

The present paper provides plasma wave characteristics observed around slow-mode shocks in the geomagnetic tail region using the Plasma Wave Instrument (PWI) and Low Energy Particle experiment (LEP) onboard Geotail spacecraft. We also apply the direction finding method to the Electrostatic Solitary Waves (ESW) observed in the upstream region. By the direction finding analyses, we found that there exist counterstreaming ESW in the foreshock. Further, we show the observed electron velocity distribution is consistent with the counterstreaming ESW. We propose the observation model that conterstreaming ESW are emitted in the foreshock region of the slow-mode shock and in the distant neutral line.