Resting on the Yalta beach, swimming in the Black Sea water, it is difficult to imagine that particles of this very water once washed the coast of Greenland or Antarctica. But this is nothing impossible, because the World Ocean (together with all its bays and seas) is a single whole. In some places, rather fast, in some places slow, currents of the World Ocean connect its most remote corners.
Acquaintance with them happened a very long time ago. The Spaniard Ponce de Leon (in 1513) went to sea to find the "Happy Islands". The ship landed in a jet of Florida currents, which turned out to be so strong that sailboats could not cope with it. In the stream of the Northern Equatorial Current Columbus sailed to America. Returning home, he said that "the waters move with the sky in a westerly direction." American merchant sailors learned about the existence of the Gulf Stream in the 18th century.
The currents of the oceans, or rather their speed and direction, were first determined by the drift of the ships that have strayed from the intended course. The wreckage of the wrecked vessels also helped determine their direction. Random items floating in the sea were not enough, so sailors began throwing clogged bottles overboard into which they put a postcard. The finder of the “trophy” indicated the place where he found the bottle, and sent the card by mail. Such messages are called "bottled mail." Later, the bottles began to be replaced with waterproof envelopes made of plastic.
The main role in the formation of surface currents is played by winds. The Northern Equatorial Stream (in the
Atlantic Ocean) drives water into the
Caribbean Sea, from where it flows through the Strait of Florida and gives rise to the Gulf Stream. Kuroshio originates in the Pacific Ocean.
The warm Gulf Stream reaches the European shores and flows into the Arctic Ocean and the Barents Sea, from which it returns already with the cold Greenland Current. On the road, the Gulf Stream loses some of the water. This water forms a circular current in the North Atlantic.
The words “warm” or “cold” should not always be understood literally. These names are flows that violate the latitudinal distribution of temperature in the ocean, if the water in them is colder or warmer than the surrounding water.
For a long time it was believed that powerful currents of the oceans, such as the Gulf Stream and Kuroshio, flow like rivers in the ocean. They actually differ from the surrounding water by salinity, color and temperature, but there is no continuous flow in them. The Gulf Stream, for example, is divided into separate jets, some of which deviate to the side and then completely separate from the main stream.
Not so long ago it became known about the existence of a whole system of bottom currents. They are formed as a result of lowering the shelf waters of the Antarctic to the bottom of the World Ocean. Thus, sedimentary material is transported and unique unidirectional flows are created, like waves in the coastal zone of the sea.
The currents of the oceans are transporters of cold and heat, larvae of fish, plankton, and the path of movement of cyclones. The frontal zone in the ocean is very interesting. Mixing of waters of different temperatures occurs quite rapidly.
Currents play a huge role in ocean life. They affect fish distribution, weather and climate.
To date, British scientists have compiled the most accurate map of the oceans. Its basis was the results of observations of the GOCE satellite. This map is designed to help climatologists in the development of computer models of the state of affairs on our planet.