Power variations of Schumann resonances related to El Niño and La Niña phenomena

Abstract

A three dimensional Finite Difference Time Domain (FDTD) model ofthe Earth-ionosphere cavity with the realistic conductivity profile is employed to study the intensity variations of Schumann resonances (SR) associated with the El Niño and La Niñia phenomena. Comparison of the results derived from our FDTD model and the previous studies by other authors on related subjects shows that the intensity of the Schumann resonances varies with the spatial shifts of the thunderstorm regions under El Niño and La Niña conditions. Due to the different spatial field distributions of SR electrical and magnetic components in the Earth-ionosphere cavity, the different power variation patterns are clearly observed in the electrical and magnetic components with the motion of the thunderstorm center in our FDTD results. A new method is proposed to detect the shifts of the thunderstorm regions related to the El Niño and La Niña phenomena using the combination of both electrical and magnetic components of Schumann resonances at a single station. Copyright 2007 by the American Geophysical Union.