Seasonal variations of global lightning activityextracted from Schumann resonances using a geneticalgorithm method

摘要

A three-dimensional Finite Difference Time Domain (FDTD) model of the Earth-ionosphere cavity with a realistic conductivity profile is employed to study the globallightning activity using the observed intensity variations of Schumann resonances (SR). Comparison of the results derived from our FDTD model and the previous studiesby other authors on. related subjects shows that Schumann resonance is a good probeto indicate the seasonal variations of lightning activity in three main thunderstorm regions(Africa, southeast Asia, and South America). An inverse method based on geneticalgorithms is developed to extract information on lightning intensity in these three regionsfrom observed SR intensity data. Seasonal variations of the lightning activity in threethunderstorm centers'are clearly observed in our results. Different SR frequency variationsassociated with seasonal variations of global lighting activity are also discussed.