SNOWFALL TIME SERIES COMPARISON BETWEEN APENNINES AND BALKANS PENINSULAS - A CLIMATE CHANGE CHALLENGE

Precipitation long-term time series are important source for the climate variability evaluation. In this work snowfall records for Apennines Peninsula sites of Modena (34 m asl, since 1830 till 2005) and Abetone (1390 m asl, since 1969 till 2005) together to Balkans Peninsula sites of Sarajevo (630 m asl, since 1888 till 2005) and Mount Bjelasnica (2067 m asl, since 1950 till 2005) are examined. Total annually (seasonally) snowfall amounts are discussed using a moving average over 30 years. From the moving averages it can be noted a quasi-linear downward trend for the recent period (from 1960 till 2000), but seemingly interrupted in the last several years. Moreover, in order to obtain smooth signal and more clear indications of possible climate oscillations, the snow precipitation signal has been filtered with one of the known wavelet transforms (the discrete Meyer wavelet is applied). Apparently, from the 3-level and especially from the 4-level approximations of the wavelet transform, oscillatory thirty/forty year’s snowfalls periods can be distinguished also in the past 150 years. The coincidence of snowfalls series either at Apennines or at Balkans Peninsula with the North Atlantic Oscillation (NAO) is found.