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)

9:15 AM - 9:30 AM

[PEM13-02] MMS Fast Plasma Investigation (FPI) observations at and near the electron and ion diffusion regions as a function of guide field

*Barbara L Giles1, James L Burch2, Tai Duc Phan4, James Webster13, Levon A Avanov1,5, Roy B Torbert2,3, Scott A Boardsen1,5, Michael O Chandler6, Li-Jen Chen1,5, Victoria N Coffey6, John C Dorelli1, Robert E Ergun7, Stephen Fuselier2, Kevin Genestreti2, Daniel Gershman1,5, Benoit Lavraud8, David A Mackler1,10, Thomas E Moore1, William R Paterson1, Craig J Pollock9, Amy C Rager1,10, Christopher T Russell11, Yoshifumi Saito12, Conrad Schiff1, Jason R Shuster1,5, Susanne E Smith1,10, Robert J Strangeway11, Adolfo Figueroa-Viñas1, Shan Wang5, Frederick Wilder7, Eftyhia Zesta1 (1.NASA Goddard Space Flight Center, 2.Southwest Research Institute, 3.Univ of New Hampshire, 4.Univ of California, Berkeley, 5.Univ of Maryland, College Park, 6.NASA Marshall Space Flight Center, 7.LASP, Univ of Colorado, 8.Research Inst in Astrophysics and Planetology, Toulouse, France, 9.Denali Scientific, 10.Catholic Univ of America, 11.Univ of California, Los Angeles, 12.Institute for Space Science, Sagamihara, Japan, 13.Rice Univ)

Keywords:magnetic reconnection, Magnetospheric Multiscale mission, Fast Plasma Investigation

Observed ion and electron distributions are compared for asymmetric reconnection events, categorized by weak-, moderate-, and strong-guide field. Several of the structures noted have been demonstrated in simulations and others have not been predicted or explained to date. We report on these observations and their persistence. In particular, we highlight counter streaming low-energy ion distributions that are seen to persist regardless of increasing guide-field. Distributions of this type were first published by Burch and Phan [GRL, 2016] for an 8 Dec 2015 event and by Wang et al. [GRL, 2016] for a 16 Oct 2015 event. Wang et al. showed the distributions were produced by the reflection of magnetosheath ions by the normal electric field at the magnetopause. This report presents further results on the relationship between the counter streaming ions and electron distributions and show the counter streaming ions traversing the magnetosheath, X-line, and in one case the electron stagnation point. We suggest the counterstreaming ions become the source of D-shaped distributions at points where the field line opening is indicated by the electron distributions. In addition, we suggest they become the source of ion crescent distributions that result from acceleration of ions by the reconnection electric field.