Response of the polar electrojets in the evening sector to polar magnetic substorms

Journal Article · Sat Sep 01 04:00:00 EDT 1973 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/JA078i025p05559· OSTI ID:4342304

Rostoker, Gordon; Kisabeth, Jerry L.

Several studies have established the existence of an eastward electrojet in the evening sector during periods of magnetospheric activity. It is shown that this electrojet may exist in such a state that it does not fluctuate in conjunction with the substorm-associated westward electrojet. However, it is also seen that the eastward electrojet may intensify at the time of the onset of a polar magnetic substorm. Studies of the evening sector auroral zone reveal that it is generally dominated by the eastward electrojet and that during substorm activity the westward electrojet in the midnight sector intensities and expands into the evening sector and occupies a narrow latitudinal regime north of the poleward border of ihe eastward jet. The exact configuration of the electrojets in the evening sector is confirmed by using model current system calculations. It is shown that the growth of the eastward electrojet in the evening sector may be the signature of the onset of the expansive phase of a substorm in the midnight sector. Thus it is not possible to consider the growth of the eastward electrojet as a unique signature of the growth phase of a substorm.

• Research Organization: Institute of Earth and Planetary Physics, University of Alberta, Edmonton, Alberta, Canada
• Sponsoring Organization: USDOE
• NSA Number: NSA-29-022168
• OSTI ID: 4342304
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: 25 Vol. 78; ISSN 0148-0227
• Publisher: American Geophysical Union
• Country of Publication: United States
• Language: English

Related Subjects

*ELECTROJETS-- DAILY VARIATIONS
*MAGNETIC BAYS-- ELECTROJETS
79 ASTRONOMY AND ASTROPHYSICS
MAGNETOSPHERE
MATHEMATICAL MODELS