Carpathian Journal of Earth and Environmental Sciences

This paper reports on the applicability of wavelet analysis to the study of multi-scale temporal patterns in soil radon gas compared to the conventional time series analysis (TSA). Both methods delivered good modeling results for the studied 15 minutes sampled time series. The main achievement of the wavelet method is the identification and numerical characterization of the subtle semi-diurnal (12 h) periodicity. Unlike the other time series components (cycle, diurnal periodicity etc.), the semi-diurnal periodicity is the only temporal feature which is the same in the studied July (summer) and December (winter) time series.