Compression of the Earth's magnetotail by interplanetary shocks directly drives transient magnetic flux closure

B Hubert*, M Palmroth, TV Laitinen, P Janhunen, SE Milan, A Grocott, SWH Cowley, T Pulkkinen, JC Gerard

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review


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 similar to 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.

Original languageEnglish
Article number10105
Number of pages4
JournalGeophysical Research Letters
Issue number10
Publication statusPublished - 31 May 2006
MoE publication typeA1 Journal article-refereed



Cite this