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

Nakamura, Rumi, Genestreti, Kevin J., Nakamura, Takuma, Baumjohann, Wolfgang, Varsani, Ali, Nagai, Tsugunobu, Bessho, Naoki, Burch, James L., Denton, Richard E., Eastwood, Jonathan P., Ergun, Robert E., Gershman, Daniel J., Giles, Barbara L., Hasegawa, Hiroshi, Hesse, Michael, Lindqvist, Per‐Arne, Russell, Christopher T., Stawarz, Julia, Strangeway, Robert J. and Torbert, Roy B. (2019) Structure of the Current Sheet in the 11 July 2017 Electron Diffusion Region Event. Journal of Geophysical Research: Space Physics, 124 (2). pp. 1173-1186. ISSN 2169-9380

JGR Space Physics - 2018 - Nakamura - Structure of the Current Sheet in the 11 July 2017 Electron Diffusion Region Event.pdf - Published Version
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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.

Item Type: Article
Additional Information: Funding Information: This work was supported by the Austrian Science Fund (FWF): I2016‐ N20 and I3506‐N27. R. E. D. was supported by NASA grant NNX14AC38G. The work of T. N. at ISAS/JAXA is supported by JSPS KAKENHI 17H06140. The work by H. H. was supported by JSPS Grant‐in‐Aid for Scientific Research KAKENHI 15K05306. The MMS data are publicly available via NASA resources and the Science Data Center at CU/LASP ( public/). We thank L. J. Chen, M. Hoshino, and H. Ji for the valuable discussions.
Uncontrolled Keywords: current sheet, electron diffusion region, magnetic reconnection, Magnetospheric Multiscale (MMS)
Subjects: F300 Physics
F500 Astronomy
Department: Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Depositing User: Rachel Branson
Date Deposited: 18 Jan 2023 15:49
Last Modified: 18 Jan 2023 16:00

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