2011 SuperDARN Workshop
Analysis of HF radar observations of ionospheric backscatter during geomagnetically quiet periods
T.A. Kane (1), R.A. Makarevich (2), A.J. McDonald (1)
(1) Department of Physics, La Trobe University, Victoria, Australia
(2) Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, USA
abstract. Coherent HF backscatter detected by the TIGER SuperDARN radar (Bruny Island, 43.38? S, 147.23? E, geographic) during geomagnetically quiet periods is analysed statistically in order to identify the controlling factors of backscatter occurrence in the F-region ionosphere. The occurrence of F-region backscatter is shown to exhibit distinct diurnal, seasonal and solar cycle variations. The backscatter data is compared to values of F-region peak electron density (NmF2) from the IRI-2007 model and with data from nearby ionosondes for validation. Pedersen conductance values of the underlying E region are also modelled and compared with the backscatter data. During the night, the amount of backscatter is shown to vary directly with the magnitude of NmF2. During the day, occurrence minima are shown to be associated with large E-region conductances. This suggests that solar illumination restricts the production of F-region irregularities during the day.