Amplitude modulation of VLF emission and absorption of cosmic noise by Pc5 geomagnetic pulsations in the period of geomagnetic storms on October 30?31, 2003

Modulation of the VLF emission and riometric absorption by Pc5 geomagnetic pulsations is studied in the period of strong geomagnetic disturbances on October 30-31, 2003. Some conclusions about the regime of pitch-angular diffusion into the loss cone are made. The better coincidence of VLF emission modulation with geomagnetic pulsations in other longitude sectors is explained by the global character of excitation of the pulsations and by damping of their amplitudes at the meridian of observation of the VLF emission, which is associated with intensification of auroral electrojets.[PUBLICATION ABSTRACT]