Considerations of A Two-Fluid Heliospheric Plasma Dynamics Under Dominant Electron Pressure

Electrons in plasma physics mostly are the underestimated species, since usually they only have to guarantee electric quasineutrality, but don’t count in terms of mass-, momentum-, and energy flows. This is different in space plasmas like the heliospheric plasma, especially the plasma downstream of the solar wind termination shock. Here it has become evident more recently that electrons dominate the plasma pressure and, connected with that, the plasma energy flow. Under these conditions a two-fluid plasma theory is needed to adequately describe fields and flows. We first here develop a pure two-fluid thermodynamics of such two-fluid plasmas and then study the actual situation in case of the heliospheric plasma that the electron pressure is dominating over the proton pressure. Under such auspices the electron pressure determines the mass- and momentum flows of the plasma and in fact decreases with the decrease of bulk velocity of the flow

A multi-spacecraft analysis of energy transfer associated with near-Earth magnetic reconnection

<p>We present an analysis of energy transfers in a reconnecting near-Earth plasma, obtained by interpreting MMS data within the framework of multi-fluid plasma theory. In our analysis, energy transfers are calculated and examined locally. This way, correlations between different mechanisms of energy exchange can be retrieved in all spatial and temporal detail provided by the high-frequency, multi-point sampling capacity of the four MMS satellites. <br>In particular, compressional effects are separated from effective sources in the energy density evolution equations, allowing to distinguish whether some effective energy transfer is occurring locally. A large database of MMS encounters with reconnecting current sheets is exploited in order to assess the statistical validity of all results presented.</p>