Dissipation Region Structure in Asymmetric Magnetic Reconnection

The dissipation region associated with magnetic reconnection is the region, typically of size a few or many ion inertia lengths, around the reconnection site where significant electromagnetic energy conversion occurs. 2-D particle-in-cell simulations are used to determine the characteristic structures of this region for the case of asymmetric reconnection, which is the most prevalent form of reconnection at the sub-solar magnetosphere, at the sun, and most likely in much of astrophysics. Among the features probed are the size and location of parallel electric fields, energy conversion, violation of the frozen-in condition, electron pressure anisotropy, non-gyrotropy of the electron distribution, electron velocity shear region and resulting flow vortices, and super-Alfvenic electron outflows. Comparison is made with observations from Polar and the THEMIS satellites. Initial results from extension of the simulations to 3D will also be discussed.