JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Oral

P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM13] [EE] Exploring space plasma processes with Magnetospheric Multiscale (MMS) mission

Sat. May 20, 2017 9:00 AM - 10:30 AM 105 (International Conference Hall 1F)

convener:Hiroshi Hasegawa(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency), Thomas Earle Moore(NASA Goddard Space Flight Ctr), Benoit Lavraud(IRAP), Seiji Zenitani(NAOJ National Astronomical Observatory of Japan), Chairperson:Hiroshi Hasegawa(Institute of Space and Astronautical Science, JAXA)

10:15 AM - 10:30 AM

[PEM13-06] Energy transfer and electron dynamics in a kinetic Alfvén wave

*Daniel J Gershman1,2, Adolfo Viñas2, John Dorelli2, Scott Boardsen2, Levon Avanov1,2, Paul Bellan3, Steven Schwartz4, Benoit Lavraud5, Victoria Coffey6, Michael Chandler6, Yoshifumi Saito7, William Paterson2, Stephen Fuselier8, Robert Ergun9, Robert Strangeway10, Christopher Russell10, Barbara Giles2, Craig Pollock2, Roy Torbert11, James Burch8 (1.University of Maryland, College Park, 2.NASA Goddard Space Flight Center, 3.California Institute of Technology, 4.Imperial College London, 5.Université de Toulouse, 6.NASA Marshall Space Flight Center, 7.JAXA Institute of Space and Astronautical Science, 8.Southwest Research Institute, 9.University of Colorado, Boulder, CO, 10.University of California, Los Angeles, 11.University of New Hampshire, Durham)

Keywords:kinetic alfven wave, plasma physics, plasma wave

Kinetic Alfvén waves (KAW) provide a mechanism for the transfer of energy in plasmas throughout the universe. The detailed properties of these waves have been elusive due to limits on plasma instrumentation. However, NASA’s Magnetospheric Multiscale (MMS) mission provides high resolution particle and fields instrumentation suitable to resolve kinetic-scale physics. On 30 December 2015, MMS resolved a monochromatic KAW in a magnetopause reconnection exhaust. Through determination of the three-dimensional wavevector, particle currents, and pressure-gradient driven electric fields, we are able to observe the conservative energy transfer between the wave field and plasma particles for the first time.

In addition to resolving wave fluctuations, we identify a dynamically significant population of non-linearly trapped electrons. These electrons are trapped within a kinetic scale magnetic mirror formed by the parallel magnetic field fluctuations of the KAW. This population, which accounted for ~50% of the density fluctuations within the wave, may have inhibited Landau and transit-time damping of the KAW, enabling its stable propagation and transport of energy away from the reconnection X-line.