کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1768120 1020214 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
On the occurrence of auroral westward flow channels and substorm phase
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم فضا و نجوم
پیش نمایش صفحه اول مقاله
On the occurrence of auroral westward flow channels and substorm phase
چکیده انگلیسی

Auroral westward flow channels (AWFCs) are intense, narrow channels of westward drift overlapping the equatorward edge of the auroral oval in the pre-magnetic midnight sector. They are a close relative of the sub-auroral polarisation stream which encompasses polarisation jets, a phenomenon also known as sub-auroral ion drift events. Recent observations made with the Tasman Geospace Environment Radar (TIGER) (147.2°E, 43.4°S Geodetic; 55.0° Geomagnetic) have revealed close associations between the appearance of AWFCs and substorm onset, and their subsequent decay toward the end of recovery phase. In fact, in terms of electric field strength, they are the strongest signatures of substorms in the ionospheric convection (>50 mV m−1). In terms of electric potential difference (>10 kV), they also represent a substantial fraction of the total potential difference generated during substorms. The AWFCs exhibit a diverse range of behaviour, there being no typical event. The radar observations show that radial polarisation fields sometimes oscillate towards and away from the Earth, and bifurcate, within regions of closed flux in the magnetotail throughout substorm evolution. We have identified every AWFC observed by TIGER during the first year of operation, 2000. Simple statistical arguments imply that one, if not more, AWFC probably occurs during every substorm. AWFCs are a fundamental aspect of substorm evolution.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Advances in Space Research - Volume 38, Issue 8, 2006, Pages 1755–1762
نویسندگان
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