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
Danube–Black Sea Canal Danube-Black Sea Canal. Danube–Black Sea Canal The Danube–Black Sea Canal () is a navigable canal in Romania, which runs from Cernavodă, on the Danube river, to Constanța (southern arm, the main branch), and to Năvodari (northern arm), on the Black Sea. Administrated from Agigea, it is an important part of the European canal system that links the North Sea (through the Rhine–Main–Danube Canal) to the Black Sea. The main branch of the canal, with a length of , which connects the Port of Cernavodă with the Port of Constanța, was built between 1976–1984, while the north branch, known as the