NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Magnetic field configuration of the theta auroraA magnetic configuration of the open magnetosphere is described which is conducive to the formation of the theta aurora when the IMF has a significant northward component. A magnetic field topology and polar cap configuration, derived from a quantitative model of the open magnetosphere that incorporates Crooker's antiparallel merging hypothesis, are presented. Under this hypothesis, when the IMF has a northward component, the dayside merging line bifurcates, leaving a large fraction of the subsolar magnetopause untouched by the merging process. The polar cap, defined by tracing magnetic field lines that connect from the solar wind to the earth, is similarly bifurcated, leaving a sun-aligned stagnation region that is not magnetically connected to the solar wind and may plausibly be associated with the sun-aligned 'bar' of the theta aurora. The model provides testable predictions with regard to the position of this 'convection gap' in both Northern and Southern Hemispheres as functions of IMF direction.
Document ID
19900043981
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Toffoletto, F. R.
(Rice Univ. Houston, TX, United States)
Hill, T. W.
(Rice University Houston, TX, United States)
Date Acquired
August 14, 2013
Publication Date
April 1, 1990
Publication Information
Publication: Geophysical Research Letters
Volume: 17
ISSN: 0094-8276
Subject Category
Geophysics
Accession Number
90A31036
Funding Number(s)
CONTRACT_GRANT: NSF ATM-88-22622
CONTRACT_GRANT: NAGW-482
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available