Spectral analysis of scale invariance in the temporal structure of precipitation in Mainland Portugal

Abstract

The temporal structure of precipitation was investigated by means of spectral analysis of daily precipitation, measured with non-recording gauges, over a period of 54 years. The data were recorded at eight locations in Mainland Portugal. Analysis of the precipitation intensity showed that scaling is present in the data, from one day up to more than one month. Empirical exponents describing the scaling of the energy spectra of the precipitation intensity were determined. Results showed that spectral analysis is able to quantify differences in precipitation variability, taking into account the behaviour observed across scales.