TY - JOUR

T1 - Near-Earth plasma sheet boundary dynamics during substorm dipolarization 3. Space science

AU - Nakamura, Rumi

AU - Nagai, Tsugunobu

AU - Birn, Joachim

AU - Sergeev, Victor A.

AU - Le Contel, Olivier

AU - Varsani, Ali

AU - Baumjohann, Wolfgang

AU - Nakamura, Takuma

AU - Apatenkov, Sergey

AU - Artemyev, Anton

AU - Ergun, Robert E.

AU - Fuselier, Stephen A.

AU - Gershman, Daniel J.

AU - Giles, Barbara J.

AU - Khotyaintsev, Yuri V.

AU - Lindqvist, Per Arne

AU - Magnes, Werner

AU - Mauk, Barry

AU - Russell, Christopher T.

AU - Singer, Howard J.

AU - Stawarz, Julia

AU - Strangeway, Robert J.

AU - Anderson, Brian

AU - Bromund, Ken R.

AU - Fischer, David

AU - Kepko, Laurence

AU - Le, Guan

AU - Plaschke, Ferdinand

AU - Slavin, James A.

AU - Cohen, Ian

AU - Jaynes, Allison

AU - Turner, Drew L.

PY - 2017/12/1

Y1 - 2017/12/1

N2 - We report on the large-scale evolution of dipolarization in the near-Earth plasma sheet during an intense (AL ∼ -1000 nT) substorm on August 10, 2016, when multiple spacecraft at radial distances between 4 and 15 R E were present in the night-side magnetosphere. This global dipolarization consisted of multiple short-timescale (a couple of minutes) B z disturbances detected by spacecraft distributed over 9 MLT, consistent with the large-scale substorm current wedge observed by ground-based magnetometers. The four spacecraft of the Magnetospheric Multiscale were located in the southern hemisphere plasma sheet and observed fast flow disturbances associated with this dipolarization. The high-time-resolution measurements from MMS enable us to detect the rapid motion of the field structures and flow disturbances separately. A distinct pattern of the flow and field disturbance near the plasma boundaries was found. We suggest that a vortex motion created around the localized flows resulted in another field-aligned current system at the off-equatorial side of the BBF-associated R1/R2 systems, as was predicted by the MHD simulation of a localized reconnection jet. The observations by GOES and Geotail, which were located in the opposite hemisphere and local time, support this view. We demonstrate that the processes of both Earthward flow braking and of accumulated magnetic flux evolving tailward also control the dynamics in the boundary region of the near-Earth plasma sheet.

AB - We report on the large-scale evolution of dipolarization in the near-Earth plasma sheet during an intense (AL ∼ -1000 nT) substorm on August 10, 2016, when multiple spacecraft at radial distances between 4 and 15 R E were present in the night-side magnetosphere. This global dipolarization consisted of multiple short-timescale (a couple of minutes) B z disturbances detected by spacecraft distributed over 9 MLT, consistent with the large-scale substorm current wedge observed by ground-based magnetometers. The four spacecraft of the Magnetospheric Multiscale were located in the southern hemisphere plasma sheet and observed fast flow disturbances associated with this dipolarization. The high-time-resolution measurements from MMS enable us to detect the rapid motion of the field structures and flow disturbances separately. A distinct pattern of the flow and field disturbance near the plasma boundaries was found. We suggest that a vortex motion created around the localized flows resulted in another field-aligned current system at the off-equatorial side of the BBF-associated R1/R2 systems, as was predicted by the MHD simulation of a localized reconnection jet. The observations by GOES and Geotail, which were located in the opposite hemisphere and local time, support this view. We demonstrate that the processes of both Earthward flow braking and of accumulated magnetic flux evolving tailward also control the dynamics in the boundary region of the near-Earth plasma sheet.

KW - Dipolarization

KW - Field-aligned current

KW - Plasma sheet boundary layer

KW - Substorm

UR - http://www.scopus.com/inward/record.url?scp=85029680489&partnerID=8YFLogxK

U2 - 10.1186/s40623-017-0707-2

DO - 10.1186/s40623-017-0707-2

M3 - Article

AN - SCOPUS:85029680489

VL - 69

JO - Earth, Planets and Space

JF - Earth, Planets and Space

SN - 1343-8832

IS - 1

M1 - 129

ER -