Non-thermal plasma observations using EISCAT: Aspect angle dependence

Winser, K. J., Lockwood, M. ORCID: https://orcid.org/0000-0002-7397-2172 and Jones, G. O. L. (1987) Non-thermal plasma observations using EISCAT: Aspect angle dependence. Geophysical Research Letters, 14 (9). pp. 957-960. ISSN 0094-8276 doi: 10.1029/GL014i009p00957

Abstract/Summary

Recent observations with the EISCAT incoherent scatter radar have shown large rises in dayside, auroral plasma velocities (>2 km s^{−1}) over a wide range of latitudes and lasting about an hour. These are larger than the neutral thermal speed, and allow, for the first time, observations of a non-thermal plasma over a range of observing angles, revealing a clear angular dependence. The observed ion temperature anisotropy, deduced by assuming a Maxwellian line-of-sight ion velocity distribution, is at least 1.75, which exceeds the theoretical value for a bi-Maxwellian based on a realistic ion-neutral collision model. The aspect angle dependence of the signal spectra also indicates non-Maxwellian plasma.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/38898
Item Type	Article
Refereed	Yes
Divisions	No Reading authors. Back catalogue items Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	American Geophysical Union
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