2D Reconstruction of magnetotail EDR measured by MMS

Models for collisionless magnetic reconnection in near-Earth space are distinctly characterized as 2D or 3D. In 2D kinetic models, the frozen-in law for the electron fluid is usually broken by laminar dynamics involving structures set by the electron orbit size while in 3D models the width of the electron diffusion region is broadened by turbulent effects. We present an analysis of in situ spacecraft observations from the Earth’s magnetotail of a fortuitous encounter with an active reconnection region, mapping the observations onto a 2D spatial domain. While the event likely was perturbed by low-frequency 3D dynamics, the structure of the electron diffusion region remains consistent with results from a 2D kinetic simulation. As such, the event represents a unique validation of 2D kinetic, and laminar reconnection models.

Acknowledgement/ Data availability:

The Magnetospheric Multiscale Mission (MMS) data used in this paper is publicly available from the CU-Boulder Laboratory for Atmospheric and Space Physics MMS Data Center webpage (https://lasp.colorado.edu/mms/sdc/public/). Using the initial conditions specified in the text, the numerical data can be reproduced with the open source VPIC code available at https://github.com/lanl/vpic, as well as at https://zenodo.org/record/4041845#.X2kA1x17kuY (doi - 10.5281/zenodo.4041845). The work was funded in part by an H. I. Romnes Faculty Fellowship by the UW-Madison Office of the Vice Chancellor for Research and Graduate Education.