[109] Ocean Current System / 洋流系統, 1999

Green arrows indicate nutrient and oxygen-rich, cold, dense, and high saline currents that usually run in the deeper layers of the oceans. They tend to flow from the poles towards the equator. Red are the warm surface currents that carry tropical waters to the higher latitudes where they release energy to the air. The meeting of cold and warm waters often result in turbulent seas and stormy regions. The major ocean currents are wind-driven currents, though some ocean currents result from density and salinity variations of water.