Structure of the Current Sheet in the 11 July 2017 Electron Diffusion Region Event

Rumi Nakamura*, Kevin J. Genestreti, Takuma Nakamura, Wolfgang Baumjohann, Ali Varsani, Tsugunobu Nagai, Naoki Bessho, James L. Burch, Richard E. Denton, Jonathan P. Eastwood, Robert E. Ergun, Daniel J. Gershman, Barbara L. Giles, Hiroshi Hasegawa, Michael Hesse, Per Arne Lindqvist, Christopher T. Russell, Julia E. Stawarz, Robert J. Strangeway, Roy B. Torbert

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)
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The structure of the current sheet along the Magnetospheric Multiscale (MMS) orbit is examined during the 11 July 2017 Electron Diffusion Region (EDR) event. The location of MMS relative to the X-line is deduced and used to obtain the spatial changes in the electron parameters. The electron velocity gradient values are used to estimate the reconnection electric field sustained by nongyrotropic pressure. It is shown that the observations are consistent with theoretical expectations for an inner EDR in 2-D reconnection. That is, the magnetic field gradient scale, where the electric field due to electron nongyrotropic pressure dominates, is comparable to the gyroscale of the thermal electrons at the edge of the inner EDR. Our approximation of the MMS observations using a steady state, quasi-2-D, tailward retreating X-line was valid only for about 1.4 s. This suggests that the inner EDR is localized; that is, electron outflow jet braking takes place within an ion inertia scale from the X-line. The existence of multiple events or current sheet processes outside the EDR may play an important role in the geometry of reconnection in the near-Earth magnetotail.

Original languageEnglish
Pages (from-to)1173-1186
Number of pages14
JournalJournal of Geophysical Research: Space Physics
Issue number2
Early online date27 Feb 2019
Publication statusPublished - Feb 2019


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