ANGEO

Annales Geophysicae

ANGEO

Ann. Geophys.

1432-0576

Copernicus Publications

Göttingen, Germany

10.5194/angeo-23-1755-2005

Polar cap influx

MacDougall

¹ Jayachandran

P. T.

Dept. Electrical Engineering, University of Western Ontario, London, Ont., N6A 5B9, Canada

28 07 2005

23 5 1755 1761

2005

This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/

This article is available from https://angeo.copernicus.org/articles/23/1755/2005/angeo-23-1755-2005.html

The full text article is available as a PDF file from https://angeo.copernicus.org/articles/23/1755/2005/angeo-23-1755-2005.pdf

This study uses digital ionosonde data from a cusp latitude station (Cambridge Bay, 77° CGM lat.) to study the convection into the polar cap. Days when the IMF magnetic field was relatively steady were used. On many days it was possible to distinguish an interval near noon MLT when the ionosonde data had a different character from that at earlier and later times. Based on our data, and other published measurements, we used the interval 10:00-13:00 MLT as the cusp interval and calculated the convection into the polar cap in this interval. The integrated convection accounted for only ~1/3 of the open polar cap flux. If the convection through the prenoon/postnoon regions on either side of the cusp was calculated the remaining 2/3 of the flux could be accounted for. The characteristics of the prenoon/postnoon regions were different from the cusp region, and we attribute this to transient flank merging versus more steady frontside merging for the cusp.<p> <b>Keywords.</b> Ionosphere (Plasma convection) Magnetospheric physics (Polar cap phenomenon)