Electrostatic solitary waves associated with magnetic anomalies and wake boundary of the Moon observed by KAGUYA

Abstract

We present observations of electrostatic solitary waves (ESWs) near the Moon by SELENE (KAGUYA) in the solar wind and in the lunar wake. SELENE is a lunar orbiter with an altitude of 100 km and measured wave electric field, background magnetic field, and fluxes of ions and electrons, etc. ESWs are categorized into three types depending on different regions of observations: ESWs generated by electrons reflected and accelerated by an electric field in the wake boundary (Type A), strong ESWs generated by bi-streaming electrons mirror-reflected over the magnetic anomaly (Type B), and ESWs generated by reflected electrons when the local magnetic field is connected to the lunar surface (Type C). ESWs of Type C often alternate with Langmuir waves.