Rainfall fluctuations over Italy and their association with solar activity

Selected records from hundreds of raingauges located along the river basins of the largest Italian rivers, throughout the whole of Italy, show a fairly similar interannual variability. Analysis of the historical time series of these data determined very significant 11-yr, 22-yr and 44-yr variabilities that are possibly linked to coherent fluctuations in the high-speed solar wind precipitation into the atmosphere. The combined effect of such signals is found to explain 60% of the yearly rainfall variance.