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Magnetic reconnection in the auroral acceleration region
Author(s) -
Chaston C. C.
Publication year - 2015
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 - 10.1002/2015gl063164
Subject(s) - magnetic reconnection , physics , current sheet , particle acceleration , plasma , plasma sheet , magnetohydrodynamics , magnetic field , geophysics , context (archaeology) , acceleration , ionosphere , conjugate points , shear (geology) , computational physics , magnetosphere , classical mechanics , geology , geometry , nuclear physics , mathematics , petrology , paleontology , quantum mechanics
Evidence is presented for the operation of extreme guide field magnetic reconnection in the presence of sheared flows in a narrow current sheet through the auroral acceleration region. Using auroral imagery, magnetically conjugate particle measurements and a 3‐D reduced MHD simulation, vortical motions in a narrow, rapidly evolving auroral arc indicative of the operation of magnetic tearing are identified. An estimate of the contribution of this process to the observed rate of energy deposition at the ionosphere shows that while this contribution can be significant it remains a minor fraction of the total. These observations are placed in the context of low magnetic shear reconnection made possible in plasmas with low plasma beta.