Diurnal harmonics in Schumann resonance parameters observed on both hemispheres

Diurnal harmonics of Schumann resonance parameters have been studied for th e first time using data obtained at two sites on opposite hemispheres, Anta rctica and Greenland. Signatures of a 24-h, a 12-h, and a 8-h harmonic are clearly discernible in both data sets, but with different strength. The amp litude of the harmonics changes with season as well. The data can partly be explained on the basis of current understanding of Schumann resonances. Th eir properties are determined by the global lightning activity and by the c ondition of the upper boundary of the Earth-ionosphere wave guide. Since at mospheric tides are very important for the dynamics ol the D region/mesosph ere, some of the results may be explained in terms of these waves.