|
|
 |
|
|
Ann. Geophys., 25, 711-720, 2007
www.ann-geophys.net/25/711/2007/
© European Geosciences Union 2007
Seasonal variations in the incidence of auroral radio absorption events at very high latitude, and the influence of the magnetotail
J. K. Hargreaves
Dept. of Communication Systems, University of Lancaster, Bailrigg, Lancaster LA1 4WA, UK
Abstract. A statistical analysis has been made of the incidence of auroral radio
absorption events at South Pole, and of its dependence on basic geophysical
parameters such as season, time of day, and magnetic activity level. It is
found that at low and moderate levels of activity the incidence of events in
the winter season is at least twice that in the summer. However, at high
activity no events at all occurred during the local summer night, which
appears to be explicable as the effect of the magnetotail and the consequent
distortion of the magnetosphere when the southern polar region is tilted
strongly towards the Sun. Previous results from even higher latitudes show
the effect in an even more exaggerated form, in that both the day and night
periods of absorption activity exhibit strong seasonal variations.
Full Article in PDF (3679 KB) |
|
|
