Open AccessThe high latitude convection response to an interval of substorm activity
Author(s) -
T. K. Yeoman,
M. Pinnock
Publication year - 1996
Publication title -
annales geophysicae
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.522
H-Index - 93
eISSN - 1432-0576
pISSN - 0992-7689
DOI - 10.1007/s00585-996-0518-4
Subject(s) - substorm , geophysics , geology , ionosphere , convection , latitude , incoherent scatter , local time , universal time , magnetosphere , physics , geodesy , meteorology , plasma , quantum mechanics , astronomy , statistics , mathematics
On 17 March 1991, five clear substormonsets/intensifications took place within a three hour interval. During thisinterval ground-based data from the EISCAT incoherent scatter radar, a digitalCCD all sky camera, and an extensive array of magnetometers were available, inaddition to data from the CRRES and DMSP spacecraft, whose footprints passedover Scandinavia very close to most of the ground-based instrumentation. Thisinterval of substorm activity has been interpreted as being in support of anear-Earth current disruption model of substorm onset. In the present study theionospheric convection response, observed some four hours to the west in MLT bythe Halley HF radar in Antarctica, is related to the growth, expansion andrecovery phases of two of the substorm onsets/expansions observed in theNorthern Hemisphere. Bursts of ionospheric flow and motion of the convectionreversal boundary (CRB) are observed at Halley in response to the substormactivity and changes in the IMF. The delay between the substorm expansion phaseonset and the response in the CRB location is dependent on the local timeseparation from, and latitude of, the initial substorm onset region. Theseresults are interpreted in terms of a synthesis of the very near-Earth currentdisruption model and the near-Earth neutral line model of substorm onset