ИСТИНА

Quasi-periodical disturbances of geomagnetic field in the frequency range 5-20 Hz recorded at CHAMP satellite (altitude about 400 km) are analyzed and compared with ground magnetometer data. Occurence rate of coherent signals in the ionosphere and on ground at different frequencies has a maximum at about 8 Hz. However, no correlation of 8 Hz signal with the global thunderstorm activity is observed. The parameters of ULF-ELF signal in the F-layer are compared with the data on regional thunderstorm activity and space weather parameters. The latitudinal distribution of coherent signals and coherence between transverse components on the ground and in the ionosphere have maxima at polar latitudes. Possible scenario for ULF-ELF signal excitation in the ionosphere by a leakage of atmospheric Schumann modes or by the magnetospheric sources are discussed.