On the contributions of atmospheric pressure and wind to daily sea level in the northern Adriatic Sea

Daily sea level variability in the Adriatic Sea is studied from different data sets using Empirical Orthogonal Functions, in connection with atmospheric pressure and wind stress. The first mode explains 56-69% of total variance and consists of uniform sea level variability all over the basin, correlated with atmospheric pressure through the inverse barometer effect. The second mode explains 13-16% of variance and accounts for an along-basin sea level gradient, which is correlated with the meridional wind stress component. The first two Principal Components are used as proxies to pressure and wind-induced components of storm surges in the northern Adriatic. The analysis of the frequency of the most intense events in the 1957-2005 period shows that the wind contribution to storm surges has decreased, while no significant trends are found in the contribution of atmospheric pressure.