IRI-2012 application for IAR frequency scale calculation

Abstract:

The paper addresses a problem of ionosphere-magnetosphere interaction through Alfven wave propagation. A new approach to analysis of emission of ionospheric Alfven resonator (IAR) is proposed. We apply the IRI-2012 version of International Reference Ionosphere model to calculate difference between frequencies of adjacent harmonics (frequency scale) of IAR emission. The calculated values are compared with the frequency scale data obtained from search-coil magnetometer measurements. It appears that to reach satisfactory results it is necessary to modify IRI-2012 model replacing the vertical profile of ionospheric parameters adopted in the standard model with the profile elongated along the magnetic field lines. Subsequent improvement was obtained by the model correction with using local f₀F₂ measurements. Finally, our results showed strong correlation between the estimated and measured values of the frequency scale. Calculated f_calc versus measured f_meas values of the IAR frequency scale are shown in Figure as a result of computation based on the modified and corrected IRI-2012 model. Dashed line is the regression line running through the origin of coordinates; gray line is the line of perfect match f_calc = f_meas. The relative mean-square error of the model estimates is approximately 15%.