Climate variability in North-Western Italy through the use of reconstructed and homogenized thermo-pluviometric series.

In order to properly study climate variations, homogeneous series are needed. We have therefore analysed thirteen meteorological stations of Piedmont owned by SIMN (Hydrographic and Mareographic National Service) in the 1951-2006 period. We have set up a monthly series for every station and then we have applied the Standard Normal Homogeneity Test for their homogenization. These methods allowed us to estimate the real trend for each series. On the other hand, the nonparametric Mann-Kendall test has been used to understand the statistical meaning of the trend for the thermal-pluviometric series. We have calculated climate indices (frost days, days with no thaw, tropical nights, summer days, thermal sum, rainy days, density of precipitations) over WMO 30-years periods (1951-80, 1961-90, 1971-2000) and over the whole period