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Compression of the Earth's magnetotail by interplanetary shocks directly drives transient magnetic flux closure
Author(s) -
Hubert B.,
Palmroth M.,
Laitinen T. V.,
Janhunen P.,
Milan S. E.,
Grocott A.,
Cowley S. W. H.,
Pulkkinen T.,
Gérard J.C.
Publication year - 2006
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 - 10.1029/2006gl026008
Subject(s) - substorm , physics , interplanetary magnetic field , flux (metallurgy) , magnetic flux , solar wind , geophysics , interplanetary spaceflight , compression (physics) , quiet , closure (psychology) , shock (circulatory) , magnetohydrodynamics , mechanics , magnetic field , magnetosphere , astronomy , materials science , market economy , quantum mechanics , economics , metallurgy , thermodynamics , medicine
We use a novel method to evaluate the global opening and closure of magnetic flux in the terrestrial system, and to analyse two interplanetary shock passages that occurred during magnetically quiet periods. We find that, even under these quiet conditions, where the amount of open flux was already low, the compression of the magnetotail by the shocks still created intense but short‐lived bursts of flux closure reaching ∼130 kV, comparable to values obtained shortly after a substorm onset, although no expansion phase developed. The results, supported by a global MHD simulation of the space environment, point to a trigger mechanism of flux closure directly driven by the solar wind compression, independent of the usual substorm expansion phase process.