Effects on climate and weather: Ocean currents have significant impact on movement to heat energy and moisture between the oceans and the atmosphere as they circulate water worldwide.
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- For example, the Gulf Stream is a warm current which originates in the Gulf of Mexico and moves north towards Europe. It keeps the sea surface warm, which keeps Western Europe warmer than other areas at similar latitudes.
- The North Atlantic drift and Kuroshio warm currents bring in rainfall along the western coast of Europe and eastern coast of Japan respectively.
- Labrador, Kurile and Falkland cold currents are responsible for heavy snowfall in the affected areas during winters.
- The Benguela and Peru currents have caused the existence of the Kalahari Desert along the Western coast of South Africa and the Atacama Desert along the South American coast respectively.
- The Humboldt Current is a cold current moving off the coast of Chile and Peru. It keeps the coast cool and the northern part of Chile arid. It leads to extremely productive waters. However, when El Nino disturbs the current, Chile’s climate is also altered.
Effects on marine life: Ocean currents are important for the distribution of world’s sea life as they transport nutrients, planktons, etc from one area to another which favours the growth of fishes. The mixing of warm and cold currents lead to abundant fish catch in the coastal countries.
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- For example, ocean currents have enriched the famous fish catch areas of the North Sea, Grand Bank and George Bank near Nova Scotia, Peruvian coast, Eastern Pacific near Japan, etc.
Ease & challenges of Navigation: Since ancient times, sailors have used the knowledge of ocean currents and winds to ease navigation in sea routes around the coasts and across the globe.
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- Understanding of currents is essential to augment the speed of ships, reduce the shipping costs and fuel consumption and also to avoid obstacles such as icebergs and debris.
- Ice-free port in higher latitudes: The Arctic port of Murmansk in Russia is ice free all year as the seas near Murmansk are warmed by relatively warm Atlantic water that flows into the Barents Sea via the Norwegian Current and North-Cape Current.
- The convergence of cold and warm ocean currents causes dense fogs which creates obstacles in navigation.
Transport of Debris: Ocean currents also move the debris around the world which in turn leads to formation of icebergs as well as trash Islands.
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- For example, the Labrador Current and Falkland currents bring icebergs from Arctic and Antarctic oceans respectively into the shipping lanes in the north and South Atlantic oceans respectively.
Energy Independence: Ocean currents are emerging as a possible source of alternative energy for the coastal countries. As dense water carries an enormous amount of energy that can be captured and converted into usable form through use of water turbines.
