Storm Surge Distribution Along the Mediterranean Coast: Characteristics and Evolution

This study describes the evolution sea level extremes along the Mediterranean coasts that results from a 4-member model ensemble of model simulations covering the period 1951-2050 under the A1B emission scenario. The results are obtained by forcing a hydro-dynamical shallow water model (HYPSE) with 6-hourly meteorological fields produced by state-of-the-art global and regional climate models that have been used in the CIRCE fp6 project. The climate change signal is computed as the difference between severe storm surge statistics in the 1971-2000 and 2021-2050 periods. All sea level time series are filtered in order to cancel sea level rise and steric effects and consider only the contribution due to marine storminess. Results show that large sea level extremes occur only in the North Adriatic and in the Gulf of Gabes and this situation does not change in future climate scenarios. Further extreme values are not expected to significantly change during the next decades because of changes in storminess. However, changes in mean sea level and land subsidence (which are not considered in this study) might change significantly the frequency of coastal floods in spite of the low sensitivity of storminess to climate change.