Sea currents are large movements of sea water. They are cyclical movements that spread over thousands of kilometers. Scientists distinguish two main types of currents:
Numerous parameters influence these currents:
Oceanic currents play a major role in explaining climates on Earth. Scientists fear that global warming is disrupting these enormous climate regulators. The Gulf Stream (North Atlantic), which explains the temperate climate of Western Europe, is often cited. A slowdown or a complete stop of the Gulf Stream would cause a profound change in the climate of this entire region.
Marine currents also influence the biological cycles of many marine species due to a seasonal supply of plankton. Migratory animals use these "ecological corridors".
Surface currents form large loops on the surface of the globe called oceanic gyres. These are currents that rotate in the same direction as the prevailing winds. It is the Coriolis force (a consequence of terrestrial rotation) that explains that these currents are clockwise in the northern hemisphere and counterclockwise in the southern hemisphere. It is in the center of these gyres that all kinds of floating waste are concentrated after a journey of several thousand kilometers.
Click "2D Projection" to switch to a 2D map. Credits: NOAA (National Oceanic and Atmospheric Administration)