Evaluation of extreme storm waves in the Black Sea

ABSTRACT The objective of the present study is to give a contribution to the extreme wave climate assessment in the Black Sea, as studies of extreme storm waves are of great interest for coastal protection and maritime traffic. High resolution wind wave data sets are used to investigate trends and variability of the characteristics of extreme storm waves. Two different methodologies (Eulerian and Lagrangean) are applied to 30 years of wave hindcast from 1987 to 2016, over the Black Sea to identify extreme storm waves and also to assess the extreme wave climate. Using the Eulerian methodology, it is observed that extreme storm waves are seasonal, being more frequent during the winter and almost non-existent during the summer. Also, that some areas, as the south-eastern region of the Black Sea more prone to storm generation, in particular, during winter and autumn. For the seven locations near the coast, a considerable inter-annual variability is found in extreme values, but not so much in the mean. Statistical significance in trend adjustment was only found in two locations in the north-western coast, for extreme values. Using a Lagrangean methodology, an inter-annual variability in all storm characteristics that is found, more marked in the annual number of wave storms, maximum area affected by storm waves and maximum length, and less marked for maximum Hs in the storm waves and storm lifetime.