Evolution of the global aurora during positive IMF B-z and varying IMF B-y conditions
1997 (English)In: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol. 102, 17489-17497 p.Article in journal (Refereed) Published
The DE 1 imaging instrumentation provides a full view of the entire amoral oval every 12 min for several hours during each orbit. We examined five examples of global evolution of the aurora that occurred during the northern hemisphere winter of 1981-1982 when the a component of the interplanetary magnetic field was positive and the y component was changing sign. Evolution of an expanded amoral emission region into a theta aurora appears to require a change in the sign of B-y during northward interplanetary magnetic field (IMF). Theta aurora are formed both from expanded duskside emission regions (B-y changes from positive to negative) and dawnside emission regions (B-y changes from negative to positive), however the dawnside-originating and duskside-originating evolutions are not mirror images. The persistence of a theta aurora after its formation suggests that there may be no clear relationship between the theta aurora pattern and the instantaneous configuration of the IMF.
Place, publisher, year, edition, pages
1997. Vol. 102, 17489-17497 p.
Fusion, Plasma and Space Physics
IdentifiersURN: urn:nbn:se:kth:diva-93359DOI: 10.1029/97JA01182OAI: oai:DiVA.org:kth-93359DiVA: diva2:515735
NR 201408052012-04-152012-04-152012-04-15Bibliographically approved