Advances in plasma physics in the Earth's magnetosphere over the past five years result in large part from the implementation of electron-scale measurements from four closely-spaced probes by the NASA Magnetospheric Multiscale (MMS) mission. Of equal importance are the rapid advances in kinetic plasma simulations, which allow full 3D treatments with sufficient numbers of electrons to match the MMS measurement cadence and expose turbulent effects. These new capabilities are focused primarily on magnetic reconnection in the boundary regions of the magnetosphere, most notably the dayside magnetopause and the neutral sheet in the magnetic tail. On the day side the predictions of asymmetric reconnection are tested and, in many cases, resolved. Tail events provide detailed studies of symmetric reconnection and energetic particle acceleration. In addition to providing our first look at reconnection in space at the electron scale, MMS reveals a much more ubiquitous nature of reconnection than was previously supposed. Reconnection is found in bow shocks, Kelvin-Helmholtz vortices, magnetic flux ropes, flux transfer events, and near-tail dipolarization fronts. Our overall perspective is that magnetic reconnection is much more widespread and important to magnetospheric dynamics than we ever imagined. The detailed physics of reconnection is also being revised as we go from testing predictions of theory and modeling, many of which are turning out to be correct, to explaining new and unanticipated measurements. It is indeed an exciting time for research on magnetospheric physics in general and on magnetic reconnection in particular.


About the Speaker:

Jim Burch is an experimental space physicist investigating various aspects of the interaction of the solar wind with the magnetospheres of the Earth and Saturn and with comets. Beginning in 1996, he was P.I. of the first NASA Medium-Class Explorer mission (IMAGE), which performed pioneering global, multi-spectral imaging of plasmas populating the Earth's magnetosphere. Also starting in 1996 and continuing until 2016, he was P.I. of the Ion and Electron Sensor (IES) on the European Space Agency's Rosetta mission, which in 2014 became the first mission to rendezvous with and orbit a comet. Since 2005, he has been P.I. of the Instrument Suite Science Team for the NASA Magnetospheric Multiscale mission, which involves four large spacecraft flying in formation in the boundary layers of the Earth's magnetosphere to perform definitive experiments on Magnetic Reconnection. Reconnection is a process that explosively converts magnetic energy to particle energy and is responsible for magnetic storms and auroras as well as solar flares and numerous other energetic phenomena throughout the universe.