2011 SuperDARN Workshop
Spectral widths of F-region PolarDARN echoes, a statistical assessment
A.V. Koustov, S. Toderian, and P.T. Jayachandran
U of Saskatchewan, Saskatoon, Canada
abstract. In this report, we investigate the spectral width of F-region PolarDARN echoes as a parameter of auroral backscatter. We show that, overall, the echoes are broader in the pre-noon sector and winter time. Scatter plots of the width versus velocity show presence of narrow (< 10 Hz) and broad echoes. We show that broad echoes dominate at relatively short ranges of ~ 800-1000 km. As range (magnetic latitude) increases, narrow-width echoes become more and more frequently detected and they dominate at ranges > 1500 km. The echoes detected simultaneously by the Inuvik and Rankin Inlet radars over Resolute Bay have comparable widths with somewhat smaller values for Inuvik, consistent with slightly larger ranges of observations. By comparing the width data with the Resolute Bay CADI measurements of the electric field we show that the spectral width does not change much with the azimuth of the flow, both for simultaneously detected RKN and INV echoes, and for separate statistics. The width slightly increases with the ExB magnitude, consistent with previous reports.