JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Poster

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 1:45 PM - 3:15 PM Poster Hall (International Exhibition Hall HALL7)

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)

[PEM13-P05] Inverse Energy Dispersion of Energetic Ions Observed in the Magnetosheath

*Sun Hee Lee1, David G. Sibeck1, Kyoung-Joo Hwang1,2, Yongfu Wang3, Marcos V. D. Silveira1, Mei-Ching Fok1, Barry Mauk4, Cohen J. Ian4, Mike Ruohoniemi5, Naritoshi Kitamura6, Jim Burch7, Barbara Giles1, Roy Torbert8, Christopher T. Russell9, Mark Lester10 (1.NASA Goddard Space Flight Center, 2.Goddard Planetary and Heliophysics Institute, University of Maryland, Baltimore County, Baltimore, MD 21228, USA., 3.Institute of Space Physics and Applied Technology School of Earth and Space Sciences, Peking University, Beijing 100871, China, 4.The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd., Laurel, MD 20723, USA., 5.Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA., 6.Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA) 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa, Japan., 7.Southwest Research Institute, San Antonio, TX, USA., 8.University of New Hampshire, Durham, NH, USA., 9.University of California, Los Angeles, CA, USA., 10.Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH, United Kingdom.)

We present a case study of energetic ions observed by the Energetic Particle Detector (EPD) on the Magnetospheric Multiscale (MMS) spacecraft in the magnetosheath just outside the subsolar magnetopause that occurred at 1000 UT on December 8, 2015. As the magnetopause receded inward, the EPD observed a burst of energetic (~50-1000 keV) proton, helium, and oxygen ions that exhibited an inverse dispersion, with the lowest energy ions appearing first.
The prolonged interval of fast antisunward flow observed in the magnetosheath and transient increases in the H components of global ground magnetograms demonstrate that the burst appeared at a time when the magnetosphere was rapidly compressed.
We attribute the inverse energy dispersion to the leakage along reconnected magnetic field lines of betatron-accelerated energetic ions in the magnetosheath and a burst of reconnection has an extent of about 1.5 RE using combined Super Dual Auroral Radar Network (SuperDARN) radar and EPD observations.