Analysis of diurnal dynamics of the geomagnetic field variation spectrum

A statistical analysis of the variations of three components of the Earth’s magnetic field obtained at Almaty during 2008 is performed. It is found that in the daytime and nighttime periods, a distinct difference in the spectra of variations with periods corresponding to acoustic-gravity waves is observed. An explanation of this difference is proposed. It is based on the mechanism of change in the acoustic-gravity wave spectrum caused by the interaction of atmospheric gas with solar radiation.