Extreme wind waves on the northeastern Shelf of the Black Sea

Abstract

The research objective is an investigation of extreme storm waves in the coastal zone from Volna Village (Kerch Strait area) to Adler on the north-eastern Shelf of the Black Sea over a climatic time span. The primary research method is numerical modelling using the MIKE 21 SW spectral wave model. As a result of calculations, hourly fields of spatial distributions of key wave parameters were obtained for the Black Sea area from January 1979 to December 2023, i.e., for the past 45 years. The analysis was conducted considering the separation of the wave field into two components: wind waves and swell. The research revealed that over the last 45 years, the north-eastern coast of the Black Sea experienced the impact of 41 storms with significant wave heights exceeding 5 meters. Two November storms in 2007 and 2023 were truly extreme, with significant sea wave heights reaching 9 meters and power exceeding 500 kW/m. Average heights of storm waves along the coast varied between 4-6 meters, and average power was around 150 kW/m. The highest waves developed in the areas of Anapa, Utrish, and Idokopas. Average values of heights and powers of wind waves showed a general tendency to decrease when moving from the northwest coast to the southeast, while swell, on the contrary, increased. Several relatively homogeneous sections in terms of the development of wind waves and swell were identified in the coastal zone. In the structure of average storm waves between Volna and Anapa, wind waves absolutely dominate. Between Cape Myskhako and Idokopas, the contribution of wind waves to the total wave energy exceeds swell by 2–2.5 times. Between Arkhipo-Osipovka and Tuapse, the energy of wind waves slightly surpasses the energy of swell. Further, south of Tuapse, the contribution of swell becomes predominant. In terms of the ratio of the contribution of wind waves and swell along the coast, two distinct regions stand out: near Anapa, the overall wave climate is determined by wind waves, while in Adler, it is determined by swell.