Magnetic Reconnection, Turbulence, and Particle Acceleration: Observations in the Earth's Magnetotail

Robert E. Ergun*, K. A. Goodrich, F. D. Wilder, N. Ahmadi, J. C. Holmes, S. Eriksson, J. E. Stawarz, R. Nakamura, K. J. Genestreti, M. Hesse, J. L. Burch, Roy B. Torbert, T. D. Phan, Steven J. Schwartz, Jonathan P. Eastwood, Robert J. Strangeway, O. Le Contel, Christopher T. Russell, M. R. Argall, Per-Arne LindqvistL. J. Chen, P. A. Cassak, Barbara L. Giles, John C. Dorelli, D. Gershman, T. W. Leonard, B. Lavraud, A. Retino, W. Matthaeus, A. Vaivads

*Corresponding author for this work

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Abstract

We report observations of turbulent dissipation and particle acceleration from large-amplitude electric fields (E) associated with strong magnetic field (B) fluctuations in the Earth's plasma sheet. The turbulence occurs in a region of depleted density with anti-earthward flows followed by earthward flows suggesting ongoing magnetic reconnection. In the turbulent region, ions and electrons have a significant increase in energy, occasionally >100 keV, and strong variation. There are numerous occurrences of |E| >100 mV/m including occurrences of large potentials (>1 kV) parallel to B and occurrences with extraordinarily large J · E (J is current density). In this event, we find that the perpendicular contribution of J · E with frequencies near or below the ion cyclotron frequency (fci) provide the majority net positive J · E. Large-amplitude parallel E events with frequencies above fci to several times the lower hybrid frequency provide significant dissipation and can result in energetic electron acceleration.
Original languageEnglish
Pages (from-to)3338-3347
Number of pages10
JournalGeophysical Research Letters
Volume45
Issue number8
DOIs
Publication statusPublished - 2018
Externally publishedYes

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