Currents and associated electron scattering and bouncing near the diffusion region at Earth's magnetopause

Authors

B. Lavraud, Université Paul Sabatier
Y. C. Zhang, Université de Toulouse
Y. Vernisse, Université Paul Sabatier
Daniel J. Gershman, NASA Goddard Space Flight Center
J. Dorelli, NASA Goddard Space Flight Center
P. A. Cassak, West Virginia University
J. Dargent, University of Pisa
C. J. Pollock, NASA Goddard Space Flight Center
B. L. Giles, NASA Goddard Space Flight Center
N. Aunai, Laboratoire de Physique des Plasmas
Matthew R. Argall, University of New HampshireFollow
L. Avanov, NASA Goddard Space Flight Center
L. Avanov, NASA Goddard Space Flight Center
A. Barrie, NASA Goddard Space Flight Center
J. L. Burch, Southwest Research Institute
M. Chandler, NASA Marshall Space Flight Center
L. J. Chen, NASA Goddard Space Flight Center
G. Clark, The Johns Hopkins University
I. J. Cohen, Johns Hopkins University
V. N. Coffey, NASA Marshall Space Flight Center
J. P. Eastwood, Imperial College London
J. Egedal, University of Wisconsin
Charlie J. Farrugia, University of New HampshireFollow
Roy B. Torbert, University of New HampshireFollow
et al.

Abstract

Based on high-resolution measurements from NASA's Magnetospheric Multiscale mission, we present the dynamics of electrons associated with current systems observed near the diffusion region of magnetic reconnection at Earth's magnetopause. Using pitch angle distributions (PAD) and magnetic curvature analysis, we demonstrate the occurrence of electron scattering in the curved magnetic field of the diffusion region down to energies of 20 eV. We show that scattering occurs closer to the current sheet as the electron energy decreases. The scattering of inflowing electrons, associated with field-aligned electrostatic potentials and Hall currents, produces a new population of scattered electrons with broader PAD which bounce back and forth in the exhaust. Except at the center of the diffusion region the two populations are collocated and appear to behave adiabatically: the inflowing electron PAD focuses inward (toward lower magnetic field), while the bouncing population PAD gradually peaks at 90° away from the center (where it mirrors owing to higher magnetic field and probable field-aligned potentials).

Publication Date

3-28-2016

Journal Title

Geophysical Research Letters

Publisher

AGU

Digital Object Identifier (DOI)

https://dx.doi.org/10.1002/2016GL068359

Document Type

Article

Recommended Citation

Lavraud, B.; Zhang, Y. C.; Vernisse, Y.; Gershman, D. J.; Dorelli, J.; Cassak, P. A.; Dargent, J.; Pollock, C.; Giles, B.; Aunai, N.; Argall, M.; Avanov, L.; Barrie, A.; Burch, J.; Chandler, M.; Chen, L. -J.; Clark, G.; Cohen, I.; Coffey, V.; Eastwood, J. P.; Egedal, J.; Eriksson, S.; Ergun, R.; Farrugia, C. J.; Fuselier, S. A.; Genot, V.; Graham, D.; Grigorenko, E.; Hasegawa, H.; Jacquey, C.; Kacem, I.; Khotyaintsev, Y.; MacDonald, E.; Magnes, W.; Marchaudon, A.; Mauk, B.; Moore, T. E.; Mukai, T.; Nakamura, R.; Paterson, W.; Penou, E.; Phan, T. D.; Rager, A.; Retino, A.; Rong, Z. J.; Russell, C. T.; Saito, Y.; Sauvaud, J. -A.; Schwartz, S. J.; Shen, C.; Smith, S.; Strangeway, R.; Toledo-Redondo, S.; Torbert, R.; Turner, D. L.; Wang, S.; Yokota, S. (2016). Currents and associated electron scattering and bouncing near the diffusion region at Earth's magnetopause, GEOPHYSICAL RESEARCH LETTERS. Vol. 43, No. 7, 3042-3050. DOI: 10.1002/2016GL068359