Authors: Dominic Payne (UMD),Marc Swisdak(UMD), James Drake(UMD), Tak Chu Li (Dartmouth), Jonathan Eastwood (Imperial College)

The onset of magnetic reconnection remains an active topic of research in heliophysics due in part to its relevance to solar flare energy release.  Studies have shown that the amount of magnetic shear (guide field energy) across the polarity inversion line (PIL) plays an important role in the “switch-on” nature of onset, significantly influences the rate of energy release once reconnection has begun, and can also influence the dynamics that lead to mixed equilibrium current sheets supported by a combination of thermal and magnetic pressure gradients.

In this study, we examine the local interaction between the guide field and thermodynamic variables during reconnection onset in a region of initially depleted thermal energy and enhanced magnetic energy in a large guide field background.  We identify critical stages of the equilibration process, characterize intervals based on whether the pressure evolution is driven by changes in density or temperature, and discuss what these intervals imply about the evolution of local heat and work density.  Finally, we examine power densities associated with electromagnetic field time evolution and electromagnetic energy transfer and compare to those related to thermodynamic changes.