New evidence for a link between lightning activity and tropical upper cloud coverage

Abstract

We report new evidence for a link between lightning activity and tropical upper cloud coverage. Using 1 - 100 Hz ELF magnetic field waveform data obtained at Syowa station, we analyzed Schumann resonance (SR) spectral intensity variation to investigate characteristics of lightning activity changes. Further, we performed the cross-spectral analysis between the spectral intensity variation and the tropical upper cloud coverage at high altitude derived from infrared cloud images. It is found that the tropical upper cloud coverage and the lightning activity change with the same periodicity and a clear anti-phase relation. These results imply that the lightning activity is closely related to the meteorological dynamics in the troposphere. This fact demonstrates that tropical upper cloud coverage may be continuously monitored by SRs measured at a single site on the Earth's surface. Copyright 2005 by the American Geophysical Union.