Formation and evolution of subauroral ion drifts in the course of a substorm

dc.contributor.author	De Keyser, J.
dc.date	1999
dc.date.accessioned	2017-05-09T11:58:43Z
dc.date.available	2017-05-09T11:58:43Z
dc.identifier.uri	https://orfeo.belnet.be/handle/internal/5371
dc.description	We propose a physical mechanism that explains how "polarization jets" (PJ) or "subauroral ion drifts" (SAID) are formed in the course of a substorm and how they evolve. A PJ/SAID is considered to be the ionospheric signature of an inward moving injected plasma front. The flow shear that exists across this interface when it arrives in the vicinity of the plasmapause is responsible for the generation of intense electric fields in the premidnight sector, where PJ/SAID are observed. Quantitative simulation of this mechanism accounts for PJ/SAID width and peak drift velocity. The mechanism explains why PJ/SAID are observed poleward of or in the vicinity of the plasmapause. The inward traveling time of the injected plasma agrees with the delay between substorm onset and the apparition of PJ/SAID; the evolution of the ionospheric signature is consistent with observations as well.
dc.language	eng
dc.title	Formation and evolution of subauroral ion drifts in the course of a substorm
dc.type	Article
dc.subject.frascati	Physical sciences
dc.audience	Scientific
dc.source.title	Journal of Geophysical Research: Space Physics
dc.source.volume	104
dc.source.issue	A6
dc.source.page	12339-12349
Orfeo.peerreviewed	Yes
dc.identifier.doi	10.1029/1999JA900109
dc.identifier.scopus	2-s2.0-0000276024