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THEMIS observations of an earthward‐propagating dipolarization front
Author(s) -
Runov A.,
Angelopoulos V.,
Sitnov M. I.,
Sergeev V. A.,
Bonnell J.,
McFadden J. P.,
Larson D.,
Glassmeier K.H.,
Auster U.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl038980
Subject(s) - physics , front (military) , plasma , magnetic field , amplitude , plasma sheet , geophysics , inertial frame of reference , ion , magnetic reconnection , computational physics , astrophysics , optics , classical mechanics , meteorology , magnetosphere , quantum mechanics
We report THEMIS observations of a dipolarization front, a sharp, large‐amplitude increase in the Z ‐component of the magnetic field. The front was detected in the central plasma sheet sequentially at X = −20.1 R E (THEMIS P1 probe), at X = −16.7 R E (P2), and at X = −11.0 R E (P3/P4 pair), suggesting its earthward propagation as a coherent structure over a distance more than 10 R E at a velocity of 300 km/s. The front thickness was found to be as small as the ion inertial length. Comparison with simulations allows us to interpret the front as the leading edge of a plasma fast flow formed by a burst of magnetic reconnection in the midtail.