Climate change assessment for Mediterranean agricultural areas by statistical downscaling

In this paper we produce projections of seasonal precipitation for four Mediterranean areas: Apulia region (Italy), Ebro river basin (Spain), Po valley (Italy) and Antalyaprovince (Turkey). We performed the statistical downscalingusing Canonical Correlation Analysis (CCA) in twoversions: in one case Principal Component Analysis (PCA)filter is applied only to predictor and in the other to both predictorand predictand. After performing a validation test,CCA after PCA filter on both predictor and predictand hasbeen chosen. Sea level pressure (SLP) is used as predictor.Downscaling has been carried out for the scenarios A2 andB2 on the basis of three GCM's: the CCCma-GCM2, theCsiro-MK2 and HadCM3. Three consecutive 30-year periodshave been considered. For Summer precipitation inApulia region we also use the 500 hPa temperature (T500)as predictor, obtaining comparable results. Results show differentclimate change signals in the four areas and confirmthe need of an analysis that is capable of resolving internaldifferences within the Mediterranean region. The most robustsignal is the reduction of Summer precipitation in theEbro river basin. Other significative results are the increaseof precipitation over Apulia in Summer, the reduction overthe Po-valley in Spring and Autumn and the increase overthe Antalya province in Summer and Autumn.