thermocline science definition

A distinct layer in a large body of water, such as an ocean or lake, in which temperature changes more rapidly with depth than it does in the layers above or below. Thermoclines may be a permanent feature of the body of water in which they occur, or they may form temporarily in response to phenomena such as the solar heating of surface water during the day. Factors that affect the depth and thickness of a thermocline include seasonal weather variations, latitude and longitude, and local environmental conditions.