Anisotropic Electron Fluid Closure Validated by in situ Spacecraft Observations in the far Exhaust of Guide-Field Reconnection

Abstract:

Anisotropic electron heating predictions of the equations of state of (Lê et al,, 2009) are applied to asymmetric reconnection in the Earth's magnetosheath. Spacecraft data shows that far downstream (~100 d_i) from the X-line, both inflows and the exhaust follow the predictions of the Lê 2009 EoS, and correspond to three separate upstream sets of parameters. This reconnection event is shown to be subject to broad-scale compression. Furthermore, the model of the Lê 2009 EoS is extended to include additional perpendicular heating terms relevant to a reconnection event undergoing active magnetic compression. The agreement between the spacecraft observations and the Lê 2009 EoS emphasizes the roles of trapped and passing electrons in setting and controlling the anisotropic electron heating at large scale in naturally occurring plasma configurations.