TY - JOUR
T1 - Electric currents of a substorm current wedge on 24 February 2010
AU - Connors, Martin
AU - McPherron, Robert L.
AU - Anderson, Brian J.
AU - Korth, Haje
AU - Russell, Christopher T.
AU - Chu, Xiangning
PY - 2014/7/16
Y1 - 2014/7/16
N2 - The three-dimensional "substorm current wedge" (SCW) was postulated by McPherron et al. (1973) to explain substorm magnetic perturbations. The origin and coherence as a physical system of this important paradigm of modern space physics remained unclear, however, with progress hindered by gross undersampling, and uniqueness problems in data inversion. Complementing AMPERE (Active Magnetosphere and Planetary Electrodynamics Response Experiment) space-derived radial electric currents with ground magnetic data allowing us to determine currents from the ionosphere up, we overcome problems of uniqueness identified by Fukushima (1969, 1994). For a substorm on 24 February 2010, we quantify SCW development consistently from ground and space data. Its westward electrojet carries 0.5 MA in the more poleward part of the auroral oval, in Region 1 (R1) sense spanning midnight. The evening sector electrojet also feeds into its upward current. We thus validate the SCW concept and obtain parameters needed for quantitative study of substorms. Key Points Auroral zone electric currents should be determined from both ground and space The substorm current wedge to first order represents substorm currents well Magnetic inversions can give useful quantitative parameters of the current wedge
AB - The three-dimensional "substorm current wedge" (SCW) was postulated by McPherron et al. (1973) to explain substorm magnetic perturbations. The origin and coherence as a physical system of this important paradigm of modern space physics remained unclear, however, with progress hindered by gross undersampling, and uniqueness problems in data inversion. Complementing AMPERE (Active Magnetosphere and Planetary Electrodynamics Response Experiment) space-derived radial electric currents with ground magnetic data allowing us to determine currents from the ionosphere up, we overcome problems of uniqueness identified by Fukushima (1969, 1994). For a substorm on 24 February 2010, we quantify SCW development consistently from ground and space data. Its westward electrojet carries 0.5 MA in the more poleward part of the auroral oval, in Region 1 (R1) sense spanning midnight. The evening sector electrojet also feeds into its upward current. We thus validate the SCW concept and obtain parameters needed for quantitative study of substorms. Key Points Auroral zone electric currents should be determined from both ground and space The substorm current wedge to first order represents substorm currents well Magnetic inversions can give useful quantitative parameters of the current wedge
KW - AMPERE
KW - current wedge
KW - magnetic inversion
KW - substorms
UR - http://www.scopus.com/inward/record.url?scp=84904087194&partnerID=8YFLogxK
U2 - 10.1002/2014GL060604
DO - 10.1002/2014GL060604
M3 - Journal Article
AN - SCOPUS:84904087194
SN - 0094-8276
VL - 41
SP - 4449
EP - 4455
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 13
ER -