Jim Burch, "Advances in Magnetic Reconnection Results with MMS"
Join us on Wednesday, April 3 in White Hall G09 at 2:30 PM for a colloquium presented by Dr. Jim Burch, Senior Vice President - Space Sector at the Southwest Research Institute (San Antonio, TX). His talk is titled Advances in Magnetic Reconnection Results with the Magnetospheric Multiscale Mission.Abstract
Magnetic reconnection is a fundamental process operating in plasmas throughout the universe. It involves the conversion of magnetic energy to heat and charged particle kinetic energy and the interconnection between magnetic fields from adjacent regions of space with important astrophysical results: (1) the transfer of angular momentum within neutron stars and black holes, (2) the origin of solar and stellar flares, (3) geomagnetic storms, and (4) the aurora. Reconnection is also important in laboratory plasma physics, where it is one of the impediments to achieving controlled nuclear fusion because of its disruptive effects in magnetic containment devices.
Even though magnetic reconnection regulates transport over often-vast spatial scales, it is controlled by microphysics processes operating on scales orders of magnitude smaller. This multi-scale nature has, for many years, prevented both theoretical predictions and measurements of how magnetic reconnection operates on the kinetic level, drastically limiting our insight into the inner workings of this critical process. This situation has now changed with the launch of MMS in 2015 and the deployment of a set of four fully instrumented spacecraft in the dayside boundary region of the magnetosphere and in the magnetotail--regions where reconnection was known to occur. To solve the physics of reconnection, measurements had to be made simultaneously from four closely spaced locations at the electron time scales, which required measurements at 100 times the fastest cadence ever achieved and spacecraft separations ten times smaller than before.
The MMS measurements are guided by particle simulations, which include predictions of electron-scale plasma distributions, reconnection rates, origin of the reconnection electric field, and particle acceleration mechanisms. Many of the simulation predictions have been confirmed by MMS, and many new aspects of reconnection have been discovered. Reconnection has been found to be much more widespread than predicted, essentially occurring wherever thin current sheets are found, including within Kelvin-Helmholtz vortices, the bow shock, and throughout the magnetosheath, where turbulent reconnection often occurs.
This presentation reviews the important contributions of MMS over the past nine years and describes new measurement campaigns that are designed to investigate how the microscale physics of reconnection drives larger-scale processes in the magnetosphere.
Biography
Jim Burch is Senior Vice President of the Space Sector of Southwest Research Institute (SwRI) in San Antonio, Texas. Jim graduated from St. Mary's University in San Antonio in 1964 with a B.S. degree in Physics. He then attended graduated school in the Department of Space Science at Rice University, where he obtained a PhD in 1968. From 1968 to 1971 he served as an officer in the U.S. Army with service in Vietnam and as an instructor in the Physics Department of the U. S. Military Academy. From 1971 to 1977 Jim worked as a space scientist for NASA at the Goddard and Marshall Space Flight Centers. Since that time, he has been at SwRI. Throughout his scientific career, Jim has been an experimental space physicist with the goal of developing new instrumentation and space missions to advance the understanding of the interaction of the solar wind with the magnetospheres of the Earth, planets, and comets and the composition of ionized and neutral gases in the solar system. He has been principal investigator of the NASA IMAGE mission, which was the first to image charged particles in the Earth's magnetosphere. He has also been principal investigator of the ion and electron sensor on the European Space Agency's Rosetta comet orbiter and lander. Currently Jim is Principal Investigator of the NASA Magnetospheric Multiscale (MMS) mission, which is the first to investigate at the electron scale the plasma physics phenomenon known as magnetic reconnection. He is also currently the principal investigator of the MASPEX mass spectrometer instrument on the NASA Europa Clipper spacecraft, which will be launched on October 10, 2024, to the Jupiter moon. With unprecedented mass resolution, MASPEX will investigate the presence of complex molecules, including organics, in the thin atmosphere and in plumes originating from the internal ocean of Europa. Jim's accomplishments have been acknowledged by Fellowship in the American Geophysical Union (AGU), by the AGU Fleming and Bowie Medals, and by the NASA Distinguished Public Service Medal.