TY - JOUR
T1 - Structure of the Current Sheet in the 11 July 2017 Electron Diffusion Region Event
AU - Nakamura, Rumi
AU - Genestreti, Kevin J.
AU - Nakamura, Takuma
AU - Baumjohann, Wolfgang
AU - Varsani, Ali
AU - Nagai, Tsugunobu
AU - Bessho, Naoki
AU - Burch, James L.
AU - Denton, Richard E.
AU - Eastwood, Jonathan P.
AU - Ergun, Robert E.
AU - Gershman, Daniel J.
AU - Giles, Barbara L.
AU - Hasegawa, Hiroshi
AU - Hesse, Michael
AU - Lindqvist, Per Arne
AU - Russell, Christopher T.
AU - Stawarz, Julia E.
AU - Strangeway, Robert J.
AU - Torbert, Roy B.
N1 - 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 (https://lasp.colorado.edu/mms/sdc/ public/). We thank L. J. Chen, M. Hoshino, and H. Ji for the valuable discussions.
PY - 2019/2
Y1 - 2019/2
N2 - 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.
AB - 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.
KW - current sheet
KW - electron diffusion region
KW - magnetic reconnection
KW - Magnetospheric Multiscale (MMS)
UR - http://www.scopus.com/inward/record.url?scp=85059906842&partnerID=8YFLogxK
U2 - 10.1029/2018JA026028
DO - 10.1029/2018JA026028
M3 - Article
AN - SCOPUS:85059906842
SN - 2169-9380
VL - 124
SP - 1173
EP - 1186
JO - Journal of Geophysical Research: Space Physics
JF - Journal of Geophysical Research: Space Physics
IS - 2
ER -