Black Sea which are largely responsible for regional precipitation inputs and influence Mediterranean Sea Surface Temperatures (SST's). The relative strength of these systems also limits the amount of cold air arriving from northern regions during winter. Other influencing factors include the regional topography, as depressions and storms systems arriving from the Mediterranean are funneled through the low land around the Bosphorus, Pontic and Caucasus mountain ranges acting as wave guides, limiting the speed and paths of cyclones passing through the region. There are some islands in the Black sea that belong to Bulgaria, Romania, Turkey, and Ukraine: The Black Sea is connected
Caspian tern Caspian tern The Caspian tern ("Hydroprogne caspia") is a species of tern, with a subcosmopolitan but scattered distribution. Despite its extensive range, it is monotypic of its genus, and has no accepted subspecies. The genus name is from Ancient Greek "hudros", "water", and Latin "progne", "swallow". The specific "caspia" is from Latin and, like the English name, refers to the Caspian Sea. It is the world's largest tern with a length of , a wingspan of and a weight of . Adult birds have black legs, and a long thick red-orange bill with a small black tip. They have a