The influence of climatic circulation indexes on the rainfall amount in Calabria (Southern Italy)

Rainfall amounts, directly responsible for the availability of water resources on a specified area, are closely linked to the climate system. To highlight this relationship, the most important teleconnection indexes, based on the difference in sea level pressure between two geographic areas tagged centres of climatic action, have been taken into account. In this study, the relationship between winter precipitation, registered in Calabria (Southern Italy), and atmospheric circulation was examined using a correlation analysis with several teleconnection indexes to find useful predictors. Specific tests on the results obtained were also applied to evaluate the significance of this analysis. These results show significant and good correlations with the North Atlantic Oscillation (NAO), the East Atlantic West Russia (EA-WR), the Mediterranean Oscillation (MO) and the Scandinavian (SCA) indexes. The correlation is low or not significant for other teleconnection patterns. Moreover, a more detailed investigation was carried out considering five Rainfall Zones of the study area, characterised by different climatic conditions, and the correlations between the above mentioned teleconnection indexes and different Precipitation Categories. The results are interesting because they show some indexes closely related to low precipitation and others to severe rainfall.