Ion Larmor radius effects near a reconnection X line at the magnetopause: THEMIS observations and simulation comparison
File(s)
Author(s)
Type
Journal Article
Abstract
We report a Time History of Events and Macroscale Interactions during Substorms (THEMIS-D) spacecraft crossing of a magnetopause reconnection exhaust ~9 ion skin depths (di) downstream of an X line. The crossing was characterized by ion jetting at speeds substantially below the predicted reconnection outflow speed. In the magnetospheric inflow region THEMIS detected (a) penetration of magnetosheath ions and the resulting flows perpendicular to the reconnection plane, (b) ion outflow extending into the magnetosphere, and (c) enhanced electron parallel temperature. Comparison with a simulation suggests that these signatures are associated with the gyration of magnetosheath ions onto magnetospheric field lines due to the shift of the flow stagnation point toward the low-density magnetosphere. Our observations indicate that these effects, ~2–3 di in width, extend at least 9 di downstream of the X line. The detection of these signatures could indicate large-scale proximity of the X line but do not imply that the spacecraft was upstream of the electron diffusion region.
Date Issued
2016-08-11
Date Acceptance
2016-08-10
Citation
Geophysical Research Letters, 2016, 43 (17), pp.8844-8852
ISSN
0094-8276
Publisher
American Geophysical Union
Start Page
8844
End Page
8852
Journal / Book Title
Geophysical Research Letters
Volume
43
Issue
17
Copyright Statement
© 2016 American Geophysical Union. All Rights Reserved
Sponsor
Imperial College Trust
Science and Technology Facilities Council (STFC)
Grant Number
N/A
ST/K001051/1
Subjects
Meteorology & Atmospheric Sciences
MD Multidisciplinary
Publication Status
Published