Relation of VLF noise to solar proton events

The method of superposed epochs is used to study the variations in the inte nsity of VLF noise at Yakutsk relative to the onset of the increase in the flux of protons with energies > 10 MeV. In the summer daytime and winter ni ghttime, the VLF noise decreases to a minimum on the third day after a flar e and increases on the fourth and fifth days. Since the main sources of reg ular VLF noise are local and equatorial thunderstorm centers, the obtained results indicate that the thunderstorm activity in eastern Siberia and the African global thunderstorm center is caused by solar proton events.