Plasma Composition in the High-Altitude Cusp Region Observed by CIS Onboard Cluster II
Abstract
We present observations of the ion composition in the high-altitude cusp region obtained by the Cluster Ion Spectrometry experiments (CIS) onboard Cluster II during January and February 2001. There were three periods during which the satellites had similar orbits and crossed the north polar region in the following way: low-altitude cusp, high-altitude cusp, magnetopause crossing. During these three periods (08:00-16:00 UT of 14th January, 01:00-08:00 UT of 31th January, and 08:30-16:00 UT of 02nd February) we have seen similar ion composition in the high-altitude cusp. This region was beginning at an altitude around 10 RE and showed a sharp increase of particle energies, in particular for H+ and O+, with isotropic distributions and energies in the range 0.2 - 32 keV/e. Furthermore, in this region the temperature was higher by a factor of about 100-1000 and the density was smaller by a factor 10 than in the low-altitude cusp. Based on this features, we can suppose that high turbulence exists in this region.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2001
- Bibcode:
- 2001AGUSM..SM42A04B
- Keywords:
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- 2724 Magnetopause;
- cusp;
- and boundary layers;
- 2736 Magnetosphere/ionosphere interactions;
- 2740 Magnetospheric configuration and dynamics