Magnetosphere Seminars

Generation and Micro-scale Effects of Electrostatic Waves in an Oblique Shock Crossing

Speaker:Katy Goodrich [LASP]
Date:Tuesday, Jan 16, 2018
Time:3:30 pm
Location:LASP Space Science Building, room N100 (1st floor)

Seminar Abstract:

We present an analysis of large amplitude (>100 mV/m) electrostatic waves observed by MMS during an oblique bow shock crossing. The observed waves primarily consist of electrostatic solitary waves (ESWs), ion acoustic waves (IAWs), and electron Bernstein waves (EBWs). ESWs typically include nonlinear structures such as double layers, ion phase-space holes, electron phase-space holes. All observed waves have very short wavelengths (~100 m) and are highly localized and/or rapidly evolving. While such wave modes have been previously observed in the terrestrial bow shock, instrumental constraints have limited detailed insight into their generation and their effect on the plasma shock environment. Analysis of this oblique shock crossing shows evidence that ESWs and EBWs can be generated via current instabilities associated with magnetic turbulence, while IAWs may be generated by impulsively reflected ions. We also present evidence that these electrostatic waves can dissipate kinetic energy in the shock. This can be done through mediating momentum transfer between incoming solar wind and reflected ions or locally heating electrons.