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Ann. Geophys., 20, 1783-1793, 2002
www.ann-geophys.net/20/1783/2002/
© European Geosciences Union 2002
Influence of magnetospheric processes on winter HF radar spectra characteristics
R. André1, M. Pinnock2, J.-P. Villain3, and C. Hanuise
1LPCE/CNRS, 3A Av. de la Recherche Scientifique, 45 071 Orléans Cedex, France
2British Antarctic Survey, High Cross, Madingley Road, CB3 OET Cambridge, UK
3LSEET/CNRS, Université de Toulon et du Var, BP 132, 83 957 La Garde Cedex, France
Correspondence to: C. Hanuise (hanuise@cnrs-orleans.fr)
Abstract. This study investigates
further the relationship between regions of the magnetosphere and the
characteristics of HF radar Doppler spectra recorded in the ionospheric
projection of those regions. It builds on earlier work, which has reported a
relationship between the Doppler spectral width and the ionospheric projection
of the magnetospheric cusp region, by introducing novel techniques for
classifying the Doppler spectra recorded by the SuperDARN radars. We first
review the geophysical factors that can condition the characteristics of the
autocorrelation function (ACF) data produced by the radars. This leads to a
classification scheme of the ACF data which is then applied to a large database
compiled from winter data taken by the Northern Hemisphere Super-DARN radars.
This statistical study shows that the ACF characteristics are not randomly
distributed in space, but rather are spatially organized in the ionosphere.
This paper suggests that these regions are ordered primarily by the low energy (<approx>
1 keV) electron precipitation region and the presence of intense ULF
wave activity.
Key words. Ionosphere (auroral ionosphere;
ionosphere-magnetosphere interactions; plasma convection)
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