SM028-03
Electron firehose instability operating in the electron diffusion region
Friday, 11 December 2020: 05:38
Virtual
Alexandra Alexandrova1, Alessandro Retino2, Olivier Le Contel3, Andrey V Divin4, Daniel J Gershman5, Barbara L Giles5, Levon A Avanov5, Robert J Strangeway6, Ferdinand Plaschke7, Per-Arne Lindqvist8, Yuri Khotyaintsev9, Robert Ergun10, Stephen A Fuselier11, Rumi Nakamura12, Matthew R Argall13, David Fischer14, Roy B Torbert15 and James L Burch16, (1)Laboratoire de Physique des Plasmas, CNRS/Ecole Polytechnique/UPMC/Univ. Paris Sud/Obs. de Paris, Saint-Maur Des Fossés Cedex, France, (2)Laboratoire de Physique des Plasmas, Palaiseau, France, (3)Laboratoire de Physique des Plasmas (UMR7648), CNRS/Ecole Polytechnique/UPMC/Univ. Paris Sud/Obs. de Paris, Paris, France, (4)St. Petersburg State university, St Petersburg, Russia, (5)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (6)Univ California, Los Angeles, CA, United States, (7)IWF ÖAW, Graz, Austria, (8)KTH Royal Institute of Technology, Stockholm, Sweden, (9)IRF Swedish Institute of Space Physics, Uppsala, Sweden, (10)Laboratory for Atmospheric and Space Physics, Boulder, CO, United States, (11)Southwest Research Institute, San Antonio, TX, United States, (12)Space Research Institute, Graz, Austria, (13)University of New Hampshire, Durham, NH, United States, (14)Space Research Institute, Austrian Academy of Sciences, Graz, Austria, (15)Univ New Hampshire, Durham, NH, United States, (16)Southwest Research Institute San Antonio, San Antonio, TX, United States
Abstract:
While reconnection is expected to convert magnetic energy to the energy of plasma acceleration and heating, the opposite sense of energy conversion was recently observed by the MMS spacecraft in the vicinity of several reconnection electron diffusion regions. In the present work, we consider a magnetotail reconnection case observed by the MMS and investigate electron distributions and wave characteristics comparing four-probe measurements. We show that in localized regions close to the outer edge of the electron diffusion region, plasma is unstable to the electron firehose instability. The time of the firehose-unstable plasma is partly associated with an opposite energy conversion (E′·J<0). The results suggest that the firehose instability may play an important role in decelerating electrons in the outer electron diffusion region and could be a useful indicator for the identification of this region from the spacecraft data.
