Measure of dissipation region in collisionless magnetic reconnection

A new measure to identify dissipation regions in collisionless magnetic reconnection is proposed. This measure builds upon the measure proposed by Zenitani (PRL 2011) and is also a Lorentz invariant scalar related to nonideal energy conversion. However, this measure uses a reference frame with vanishing perpendicular electric field. The significance of this frame is discussed and the measure is applied to two-dimensional particle-in-cell simulations.