GEM reconnection challenge: Implicit kinetic simulations with the physical mass ratio

Abstract

We extend kinetic simulations of the Geospace Environment Modeling (GEM) magnetic reconnection challenge [Birn et al., J. Geophys. Res., 106, 3715, 2001] to a physical mass ratio, using the implicit Particle‐in‐Cell (PIC) code CELESTE3D which allows the use of a coarser grid and a bigger time step. We compare results for three values of the mass ratio mi/me = 25 (GEM challenge standard mass ratio), mi/me = 180 and the physical mass ratio mi/me = 1836. The results of the three simulations are compared and the scaling laws based on reconnection via nongyrotropic electron pressure are verified.