• What are ocean currents?
• Types of ocean currents
• Causes of ocean currents
• Major ocean currents in the world

We explain what marine currents are and the types that exist. In addition, the causes of its formation and the main marine currents.

Ocean currents involve both cold and warm bodies of water.

What are ocean currents?

It is called marine currents or ocean currents to a type of characteristic movement of the waters that constitute the oceans and the seas more extensive, and which are due to a multitude of factors, both the earth rotation, to the winds and the location of the continents.

Sea currents often involve masses of Water both cold and warm, which connect various climatic bands of the globe, traveling both superficially and underwater:

• The warm currents. They are surface waters that originate in the oceans of the intertropical zone and that migrate from the eastern coasts of the continents to the latitudes medium and high, against earth rotation and only in the northern hemisphere.
• The cold currents. They are waters of little temperature and great depth, which start from the intertropical or subtropical zone, and compensate the effect of the warm ones when they reach the western coasts of the continents. They are particular to the arctic regions, since in the Antarctic there is hardly a circular current around the pole.

The displacement constant of these marine currents throughout the world allows to maintain an energy and caloric cycle in the planet, which results in a set of more or less fixed climates in certain regions, such as the climates dry on the western coasts of the intertropical or subtropical zone, and warmer and more humid climate on the western coasts of the continents in the middle and high latitudes. The same occurs with salinity levels in ocean waters. This joint cycle is known asCirculationthermohaline world.

Types of ocean currents

Ocean currents present a movement generated by the earth's rotation.

We can talk about the following types of currents, according to their characteristics:

• Ocean currents. They present a constant movement generated by the earth's rotation, generally in an east-west direction in the intertropical zone, or in the opposite direction in the middle or high latitudes.
• Tidal currents. Periodic currents of daily cycle, which produces the attraction of the Moon and from Sun on the surface of the waters, that is to say, in warm waters. They displace huge amounts of water from the northern hemisphere to the south and vice versa.
• Wave currents. Produced by winds, especially storms or hurricanes, they occur on the surface of the waters and have a limited impact.
• Coastal drift currents. They are due to the meeting of the currents with the path of the relief of the coasts, which forces them to change their orientation or direction.
• Density currents. Those that originate in the contact zone between two bodies of water with different density, like those more and less saline, or more and less warm. They usually occur in straits between different seas and oceans, along the equatorial axis, or along the Arctic Circle.

Causes of ocean currents

The cold waters of the ocean rise to the surface pushing the warm ones in their path.

The three most important physical causes of ocean currents are:

• Earth movements. Both the translation and the rotation of the planet cause constant movements of the water masses, although in many cases these move in the opposite direction to the Earth's rotation.
• The planetary winds. It is not true that the winds directly cause the tides, but they do contribute to it, by displacing not only the waters of the surface (as in the swell), but also mobilizing the atmosphere to circulate heat energy from the environment, which has an impact on the water.
• The emergence of cold waters. Deep ocean waters are cold, as they are denser and have less Energy. These waters rise to the surface in specific areas of the intertropical zone, pushing the warm waters in their path.

Major ocean currents in the world

The main known marine currents are, according to the Ocean:

• Arctic Ocean.
  • West Greenland Current.
  • East Greenland Current.
  • Norway stream.
• Atlantic Ocean.
  • West Indies Stream.
  • North Atlantic current.
  • South Atlantic current.
  • Benguela current.
  • Brazilian current.
  • Cape Horn Current.
  • Canary current.
  • Caribbean current.
  • North Equatorial Current.
  • South Equatorial Current.
  • Gulf Stream.
  • Guinea current.
  • Labrador Stream.
  • Madagascar current.
  • Malvinas current.
  • Current of the north of Brazil.
  • Portugal current.
  • Spitzbergen current.
• Pacific Ocean.
  • Alaska Stream.
  • Aleutian Stream.
  • Eastern Australian Current.
  • California Stream.
  • Cromwell current.
  • Humboldt current.
  • Kamchatka Stream.
  • Kuroshio or Japan current.
  • Mindanao Stream.
  • Child stream.
  • Oyashio stream.
  • North Pacific Current.
• Indian Ocean.
  • Current of the Needles.
  • Western Australian Stream.
  • South Equatorial Current.
  • Eastern stream of Madagascar.
  • Leeuwin current.
  • Madagascar current.
  • Monsoon Stream.
  • Mozambique stream.
  • Somalia Stream.
• Antartic Ocean.
  • Antarctic current.
  • Antarctic Circumpolar Current.
  • Spin Wedell.