Aspect angle dependence of the E region irregularity velocity at large flow angles

Makarevich, R. A. and Koustov, A. V. and Senior, Andrew and Uspensky, M. and Honary, Farideh and Dyson, P. L. (2007) Aspect angle dependence of the E region irregularity velocity at large flow angles. Journal of Geophysical Research, 112. A11303. ISSN 0148-0227

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Abstract

We present the Doppler velocity observations of 1-m plasma waves in the auroral E region by the Scandinavian Twin Auroral Radar Experiment (STARE) Norway VHF coherent radar in the context of simultaneous and coincident measurements of electron and ion drift velocities determined by the European Incoherent Scatter (EISCAT) tristatic radar facility. The measurements were performed in the afternoon sector (1500–2000 MLT) at seven locations along the STARE radar beam 2 with different values of the magnetic off-perpendicular (aspect) angle α between 0.48° and 2.63° and at large angles with respect to the electron background drift ( = 55°–90°). It is demonstrated that the STARE line-of-sight velocity, normalized to the EISCAT-derived electron drift speed at large flow angles, exhibits a decrease with increasing aspect angle, and the rate of decrease is investigated as a function of the flow angle. We also compare the STARE velocity with the electron and ion drift velocity components along the STARE radar beam look direction and show that, at large aspect angles, the E region velocity is correlated (anticorrelated) with the ion (electron) drift velocity component. The results are discussed in the contexts of the linear fluid theory of the modified two-stream plasma instability and the theory of anomalous collisions.

Item Type: Journal Article
Journal or Publication Title: Journal of Geophysical Research
Additional Information: Copyright (2007) American Geophysical Union. Further reproduction or electronic distribution is not permitted
Uncontrolled Keywords: /dk/atira/pure/researchoutput/libraryofcongress/t1
Subjects:
Departments: Faculty of Science and Technology > School of Computing & Communications
Faculty of Science and Technology > Physics
Faculty of Science and Technology > Engineering
ID Code: 6720
Deposited By: ep_importer_dcs
Deposited On: 21 Apr 2008 10:46
Refereed?: Yes
Published?: Published
Last Modified: 21 Sep 2019 00:11
URI: https://eprints.lancs.ac.uk/id/eprint/6720

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