Wind driven circulation is circulation caused on the surface layer of the ocean by wind.
The layer directly affected by the wind is the roughly 100 meter-thick Ekman layer , however, wind driven circulation occurs to a depth of approximately 1000 meters. As the distribution of the wind is not constant, gathering and diffusion occurs in the Ekman transport in the Ekman layer, which in turn raises and pushes down the water below the Ekman layer, causing a current to a far greater depth. Further, as Coriolis' force changes depending on the latitude, the wind driven circulation forms Rossby waves which transmit to the west, pushing against the west side of the sea. This is called westward intensification , and the current thereby caused is called a westward boundary current . Kuroshio and the Gulf Stream are examples of this phenomenon.