Extreme waves and climatic patterns of variability in the North Atlantic Ocean and the Mediterranean Sea

The spatial and temporal variability of extreme wave climate in the North Atlantic Ocean and the Mediterranean Sea is assessed using a 31-year wave model hindcast. Seasonality accounts for 50% of the extreme wave height variability in North Atlantic Ocean and up to 70% in some areas of the Mediterranean Sea. Once seasonality is filtered out, the North Atlantic Oscillation and the Scandinavian Index are the dominant large-scale atmospheric patterns that control the interannual variability of extreme waves during winters in the North Atlantic Ocean; and to a lesser extent, the East Atlantic Oscillation also modulates extreme waves in the central part of the basin. In the Mediterranean Sea, the dominant modes are the East Atlantic and East Atlantic/ Western Russia modes which act strongly during their negative phases. In addition, this study presents a methodology enables to identify the characteristic atmospheric situation associated with extreme waves in relation with the most relevant climatic indices using atmospheric composites from the hindcast.