A mechanism for electrostatic solitary waves observed in the reconnection jet

Abstract

Magnetospheric Multiscale spacecraft (MMS) mission has observed electrostatic solitary waves (ESWs) in the reconnection jet region in the Earth's magnetotail. An ion-acoustic soliton model, based on Sagdeev pseudopotential technique, is proposed to explain these ESWs. The reconnection jet plasma is modeled by a three-component magnetized plasma consisting of hot electrons and two cold ion beams streaming parallel and anti-parallel to the magnetic field, B respectively. The model predicts four types of ion-acoustic solitons, namely, two fast and two slow ion-acoustic solitons, where one of each type propagates parallel and another anti-parallel to the ambient magnetic field, respectively. The model predicts positive potential solitons with amplitudes ∼ (51-539) V, associated bipolar electric fields with amplitudes in the range of ∼ (3-69) mV m −1 , and the soliton widths of ∼  (4.5-10.3) Debye lengths. Theoretical predictions are found to be in good agreement with the observed characteristics of ESWs in the reconnection jet region by MMS mission.