Energy Conversion Associated with Intermittent Currents in the Magnetosheath Downstream of the Quasi-Parallel Shock

Abstract

Using the data from the Magnetospheric Multiscale (MMS) mission, we studied the energy conversion between electromagnetic fields and particles (ions and electrons) in a spacecraft rest frame inside a turbulent magnetosheath downstream of the quasi-parallel shock. The results show that the energy conversion was highly intermittent in the turbulent magnetosheath, and the perpendicular electric fields dominated the energy conversion process. The energy conversion among the electromagnetic fields, ions, and electrons was related to the current intensity. In the region with weak current, the ions gained energy from electromagnetic fields, while the electron energy was released and transferred into electromagnetic fields. In contrast, in the intense current region, the energy of ions was transferred into the electromagnetic fields, but the electrons gained energy from electromagnetic fields. The results quantitatively established the relationship between energy conversion rate and current density and revealed that the energy conversion among the electromagnetic fields, ions, and electrons was related to the local current intensity inside the shocked turbulence.