EDDY

A small disturbance of wind in a large wind flow, which can produce turbulent conditions. They can also be areas of warmer air north of the main westerlies or colder air south of the westerlies. (See cut-off high or cut-off low.) In oceanic circulation, it is a circular movement of water usually formed where currents pass obstructions, between two adjacent currents flowing counter to each other, or along the edge of a permanent current.