A new mechanism for the ionospheric Alfvénresonator (IAR) excitation at middle latitudes is considered. It is shownthat the ionosphere wind system in this region is capable of sustaining thegeneration of geomagnetic perturbations that can be detected by groundmagnetometers. The general IAR dispersion relation describing the linearcoupling of the shear Alfvén and fast magnetosonic/compressional modesis obtained. The dependence of the IAR eigenfrequencies and damping rates onthe perpendicular wave number and on the ground conductivity during theday- and nighttime conditions is analyzed both analytically and numerically. Inorder to demonstrate the IAR excitation by neutral winds the power spectraof the geomagnetic perturbation on the ground surface are calculated.Furthermore, it is found that Kolmogorov spectra of the ionosphericturbulent neutral winds and the IAR eigenfrequencies lie in the samefrequency range that make it possible to enhance the IAR excitation. Therelevance of the developed theoretical model to the ground-basedobservations is stressed.
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