Ocean water is on the move, affecting your climate, your local ecosystem, and the seafood that you eat. Ocean currents, abiotic features of the environment, are continuous and directed movements of ocean water. These currents are on the ocean’s surface and in its depths, flowing both locally and globally. Winds, water density, and tides all drive ocean currents. Coastal and sea floor features influence their location, direction, and speed. Earth’s rotation results in the Coriolis Effect which also influences ocean currents.
Stratification of ocean water is a naturally occurring phenomenon that is important to the structure, circulation and productivity of the oceans. The formation of vertical stratification in the water column is a consequence of water masses with different densities. Water density is strongly influenced by temperature and salinity; with less dense, warmer surface waters floating on top of denser, colder waters. The boundary between the warmer and cold waters is called the thermocline.