Effect of electron ambient plasmas in reconnection jets and dipolarization fronts : MMS initial results

Thursday, 17 December 2015: 13:55
2018 (Moscone West)
Rumi Nakamura1, Klaus Torkar2, Maria Andriopoulou3, Harald Jeszenszky1, Ferdinand Plaschke4, Wolfgang Baumjohann1, Werner Magnes1, David Fischer4, Daniel Schmid4, Manfred Steller1, Takuma Nakamura5, Carsten Scharlemann6, Roy B Torbert7, James L Burch8, Robert E Ergun9, Per-Arne Lindqvist10, Goran Tage Marklund11, Yuri V Khotyaintsev12, Christopher T Russell13, Robert J Strangeway14, Hannes Karl Leinweber15, Brian J Anderson16, Guan Le17, Kenneth R Bromund17, Stephen A Fuselier8,18, Mark Chutter19, James A Slavin20, Larry Kepko17, Olivier Le Contel21, Craig J Pollock22, John Dorelli17, Daniel J Gershman23, Barry Mauk24, Hans Vaith7, Craig Kletzing25, Scott R Bounds25 and Kristine M Sigsbee25, (1)Space Research Institute, Austrian Academy of Sciences, Graz, Austria, (2)Austrian Academy of Sciences, Graz, Austria, (3)Austrian Academy of Sciences, Vienna, Austria, (4)IWF Institute for Space Research, Graz, Austria, (5)Los Alamos National Laboratory, Plasma Theory and App, Los Alamos, NM, United States, (6)FHWN, Wiener Neustadt, Austria, (7)University of New Hampshire Main Campus, Durham, NH, United States, (8)Southwest Research Institute, San Antonio, TX, United States, (9)University of Colorado, Laboratory for Atmospheric and Space Research, Boulder, CO, United States, (10)KTH Royal Institute of Technology, Stockholm, Sweden, (11)Royal Inst Technology, KTH/EES, Stockholm, Sweden, (12)IRF Swedish Institute of Space Physics Uppsala, Uppsala, Sweden, (13)University of California Los Angeles, IGPP/EPSS, Los Angeles, CA, United States, (14)University of California Los Angeles, Los Angeles, CA, United States, (15)Institute of Geophysics and Planetary Physics Los Angeles, Los Angeles, CA, United States, (16)Johns Hopkins University, Baltimore, MD, United States, (17)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (18)Southwest Res Inst, San Antonio, TX, United States, (19)University of New Hampshire, Durham, NH, United States, (20)University of Michigan Ann Arbor, Ann Arbor, MI, United States, (21)Laboratoire de Physique des Plasmas (UMR7648), CNRS/Ecole Polytechnique/UPMC/Univ. Paris Sud/Obs. de Paris, Paris, France, (22)NASA Goddard Space Flight Center, Heliophysics Sci. Div., Greenbelt, MD, United States, (23)University of Michigan Ann Arbor, Department of Atmospheric, Oceanic and Space Sciences, Ann Arbor, MI, United States, (24)Applied Physics Laboratory Johns Hopkins, Laurel, MD, United States, (25)University of Iowa, Iowa City, IA, United States
 With the successful launch of Magnetospheric Multiscale Misssion (MMS), it becomes possible to observe the dynamic signatures of magnetospheric transients with high-time resolution measurements of electromagnetic fields and plasma. The Active Spacecraft Potential Control (ASPOC) neutralizes the spacecraft potential by releasing positive charge produced by indium and thereby controlling the spacecraft potential in order to enable accurate measurements also in sparse plasma environments essential to study properties of reconnection. Since the current balance around the spacecraft is maintained by contribution also from the ambient plasma, predominantly electrons, ASPOC beam current values combined with spacecraft potential data from FIELDS instruments enable to deduce the ambient electron plasma parameters . Particularly, using data from multi-spacecraft measurements with different ASPOC current levels and FIELDS data, parameters on ambient electron temperature and density can be deduced.


Monitoring the environmental plasma parameters are essential to determine the accurate scales of the structure or wave length relative to plasma scales and hence to understand the physical processes. In this study we investigate the changes of the electron parameters in the transient structures such as the magnetic field disturbance forming at the front of BBF/flow bursts, called dipolarization front (DF), and reconnection jets in thin current sheets obtained by MMS mainly during the commissioning phase when the spacecraft traversed the near-Earth tail.