A new approach to the determination of the E-region drift velocity using radar aurora doppler spectral shape

In radar auroral research, Doppler spectra have been and still are being studied intensively. This is because the spectra can provide valuable information about auroral plasma irregularities. A simple model of the laminar ionospheric current is not able to explain the measured shapes and widths of the radar aurora Doppler spectra. In the present paper, a turbulent current model is used as a basis for the theoretical determination of the radar aurora Doppler spectra. The results of the theoretical calculations of the Doppler spectra are compared with some experimental data. It is found that the theoretical and experimental spectra coincide very well. The method that has been developed allows us to calculate all known basic; types of Doppler spectra which correspond to the Farley-Buneman plasma instability. This approach provides a way of developing a procedure for determination of electron drift velocities and electric fields in the auroral E-region using only a single coherent radar. As an example we use some STARE spectra to determine the electron drift velocity vectors. The values of the drift velocity vectors derived from the spectra are higher than the values determined by the STARE technique. To find out which of these results are closer to reality is possible only by analysing the simultaneous spectral measurements by the STARE radars and the EISCAT measurements of the drift velocity vectors.