ANGEO Annales Geophysicae ANGEO 1432-0576 Copernicus GmbH Göttingen, Germany 10.5194/angeo-20-1769-2002 A Statistical study of the Doppler spectral width of high-latitude ionospheric F-region echoes recorded with SuperDARN coherent HF radars Villain J.-P. 1 6 André R. 1 Pinnock M. 2 Greenwald R. A. 3 Hanuise C. 4 5 LPCE/CNRS, 3A Av. de la Recherche Scientifique, 45071 Orléans Cedex, France British Antarctic Survey, High Cross, Madingley Road, CB3 OET Cambridge, UK The Johns Hopkins University, Applied Physics Laboratory, Laurel, Maryland, USA LSEET/CNRS, Université de Toulon et du Var, BP 132, 83957 La Garde Cedex, France now at LPCE/CNRS Correspondence to: J.-P. Villain (jvillain@cnrs-orleans.fr) 30 11 1999 20 11 1769 1781 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.ann-geophys.net/20/1769/2002/angeo-20-1769-2002.html The full text article is available as a PDF file from http://www.ann-geophys.net/20/1769/2002/angeo-20-1769-2002.pdf

The HF radars of the Super Dual Auroral Radar Network (SuperDARN) provide measurements of the <b><i>E</i></b> × <b><i>B</i></b> drift of ionospheric plasma over extended regions of the high-latitude ionosphere. We have conducted a statistical study of the associated Doppler spectral width of ionospheric F-region echoes. The study has been conducted with all available radars from the Northern Hemisphere for 2 specific periods of time. Period 1 corresponds to the winter months of 1994, while period 2 covers October 1996 to March 1997. The distributions of data points and average spectral width are presented as a function of Magnetic Latitude and Magnetic Local Time. The databases are very consistent and exhibit the same features. The most stringent features are: a region of very high spectral width, collocated with the ionospheric LLBL/cusp/mantle region; an oval shaped region of high spectral width, whose equator-ward boundary matches the poleward limit of the Holzworth and Meng auroral oval. A simulation has been conducted to evaluate the geometrical and instrumental effects on the spectral width. It shows that these effects cannot account for the observed spectral features. It is then concluded that these specific spectral width characteristics are the signature of ionospheric/magnetospheric coupling phenomena.<br><br><b>Key words.</b> Ionosphere (auroral ionosphere; ionosphere-magnetosphere interactions; ionospheric irregularities)