Climatological Characteristics and Genesis Patterns of Mesoscale Atmospheric Eddies Over the Black Sea

This study presents a climatological analysis of mesoscale atmospheric eddies over the Black Sea. The analysis uses COSMO-REA6 reanalysis data from January 1995 to August 2019. A novel, objective spiral template-matching algorithm was used to identify and track eddies. This approach enabled the classification of genesis hotspots and their seasonal variability. Five distinct genesis clusters were identified: Caucasus, Caucasus-Southeast, Küre, Küre-West and Crimea. The Caucasus cluster is dominant. It accounts for over 50% of the total eddy lifespan and produces the most intense and persistent systems. This cluster is marked by thermally forced circulations that peak during summer. These circulations are driven by strong land–sea temperature contrasts, diurnal thermal cycles and orographic channelling along the Caucasus Mountains. In comparison, the eastern clusters (Caucasus and Caucasus-Southeast) produce longer-lived eddies with stronger cores. The western clusters (Küre-West and Crimea) are associated with shorter-lived eddies, weaker cores and more uniform year-round activity. The Black Sea is surrounded by mountains along most of its coastline, showing pronounced orographic control over cyclogenesis. Orography shapes both the genesis locations and eddy trajectories, explaining the observed east–west differences in structure and persistence.