The Canary Current helps keep the Sahara’s western Atlantic coast unusually cool and dry.
This cold eastern-boundary current flows southward along the coasts of Morocco and Western Sahara before turning toward the west near the tropics. It is part of the North Atlantic circulation and is fed partly by water moving south from the North Atlantic Drift.
Cold coastal water reduces evaporation and encourages stable air near the surface. Those conditions suppress cloud growth and rainfall, reinforcing the arid climate along the nearby desert coast. Upwelling also brings nutrient-rich deep water toward the surface, supporting productive fisheries despite the surrounding desert.
The current does not create the entire Sahara by itself. Subtropical high pressure, descending dry air, distance from moisture sources, and mountain effects also contribute. Its cooling influence is one reason the coastal desert can remain dry even beside the Atlantic Ocean.