TITLE:  Magnetic reconnection and the electron diffusion region: key discoveries in the MMS era

ABSTRACT:  NASA’s Magnetospheric Multiscale (MMS) mission has enabled a rapid evolution in our understanding of magnetic reconnection. Reconnection explosively releases magnetic energy stored in thin current sheets and heats and accelerates the nearby plasma. Reconnection occurs in current-carrying boundary layers in laboratory and astrophysical plasmas, including those found in and around Earth’s magnetosphere, where it is observed by MMS. In particular, MMS was designed to study the electron diffusion region (EDR). Though reconnection can effect large-scale change to a plasma system it is only enabled by the physics that occurs in the small-scale EDR. In this seminar, we provide an overview of the goals of MMS and summarize its key findings, including: (1) the features of the EDR that allow for the breaking of the frozen-in condition and the reconnection of magnetic fields, (2) the structure of the thin reconnecting current sheet and how it depends on the upstream conditions, and (3) how magnetic energy is dissipated in the EDR.