Magnetic reconnection in the auroral acceleration region

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 moti...

Full description

Saved in:
Bibliographic Details
Published in:Geophysical research letters 2015-03, Vol.42 (6), p.1646-1653
Main Author: Chaston, C. C.
Format: Article
Language:English
Subjects:
Acceleration
aurora
Auroral arcs
Auroral zones
Auroras
Current sheets
Deposition
electric fields
Energy
Energy budgets
Geophysics
Identification
Imagery
Ionosphere
Magnetic fields
Magnetic reconnection
Magnetohydrodynamics
particle acceleration
Plasmas
Plasmas (physics)
reconnection
Shear
Simulation
Tearing
tearing instability
Three dimensional
vorticity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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. Key Points Magnetic reconnection occurs in narrow discrete auroral arcs Magnetic reconnection can occur for extremely small magnetic shear Magnetic reconnection contributes
ISSN:0094-8276
1944-8007
DOI:10.1002/2015GL063164