Long description

A schematic picture of the global ocean circulation. There is a map of the world with land coloured green and the seas coloured blue. Across and joining all the oceans is a continuous band representing the continuous global ocean circulation. Warm upper waters are shaded red in the band and represent a flow from the Pacific Ocean into the Indian Ocean and finally the Atlantic Ocean, and also from the Pacific Ocean into the Atlantic Ocean through Drake Passage (south of the southern tip of South America). Once in the Atlantic Ocean the warm red current flows northwards past Europe where it cools, sinks, and changes direction to the south. The colour of the current changes to blue to represent cold, deep currents. It flows south beneath the warm current to the South Atlantic where is flows to the east before eventually returning to the Pacific and Indian Oceans where it is turned into warm currents again.