Prelude to THEMIS tail conjunction study
2007 (English)In: Annales Geophysicae, ISSN 0992-7689, E-ISSN 1432-0576, Vol. 25, no 4, 1001-1009 p.Article in journal (Refereed) Published
A close conjunction of several satellites (LANL, GOES. Polar. Geotail, and Cluster) distributed from the geostationary altitude to about 16 R-E downstream in the tail occurred during substorm activity as indicated by global auroral imaging and ground-based magnetometer data. This constellation of satellites resembles what is planned for the THEMIS (Time History of Events and Macroscopic Interactions during Substorms) mission to resolve the substorm controversy on the location of the substorm expansion onset region. In this article, we show in detail the dipolarization and dynamic changes seen by these satellites associated with two onsets of substorm intensification activity. In particular, we find that dipolarization at similar to 16 R-E downstream in the tail can occur with dawnward electric field and without plasma flow, just like some near-Earth dipolarization events reported previously. The spreading of substorm disturbances in the tail coupled with complementary ground observations indicates that the observed time sequence on the onsets of substorm disturbances favors initiation in the near-Earth region for this THEMIS-like conjunction.
Place, publisher, year, edition, pages
2007. Vol. 25, no 4, 1001-1009 p.
magnetospheric physics, magnetospheric configuration and dynamics, magnetotail, storms and substorms
IdentifiersURN: urn:nbn:se:uu:diva-150846ISI: 000246762100016OAI: oai:DiVA.org:uu-150846DiVA: diva2:409077