Humboldt Current

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Humboldt Current

The Humboldt Current , also known as the Peruvian Current , is a cold, low-salt, near-surface ocean current on the west coast of South America , named after the German natural scientist Alexander von Humboldt , who published his measurements of the cold ocean current in his book "Kosmos" in 1845 . The Humboldt Current has its origin in the Antarctic and flows north along the South American west coast of Chile and Peru . South of the equator at roughly the latitude of northern Peru or Ecuador , the current leaves the coast and turns west towards the central Pacific. In this way, the water slowly warms and mixes, then continues on its way as a warm south equatorial current.

The Humboldt Current is over 6500 km long from approx. 45 degrees south latitude to approx. 4 degrees south latitude and has a width of up to 900 kilometers. The surface temperature ( Sea Surface Temperature ; SST) can drop by up to 15 degrees Celsius and is therefore significantly colder (approx. 7 to 8 ° C) than other sea areas of the same geographical latitude. The water masses of the Humboldt Current displace other subtropical water masses from the coast and thus influence the coastal climate of Chile and Peru. The northward current together with the prevailing winds and the accompanying Ekman transport leads to an area of upwelling north of the 30th parallel south latitude . The buoyancy of nutrient-rich deep water has a direct impact on biological production. This ocean current is one of the most productive areas in the world and produces the most fish per unit area in the world. Around 18 to 20 percent of the marine fish caught worldwide are caught here. Most of the fish caught are pelagic fish: sardines , anchovies, and mackerel . This high production makes commercial fishing possible and is also responsible for a large population of marine marine mammals ( ear seals and whales ) and birds

The cold water of the Humboldt Current cools the air flowing over it before it hits the coast of South America in Chile , Peru and Ecuador . The cooled air reduces the probability of precipitation, even if clouds and fog regularly form along the coast. Because of this effect, the Humboldt Current is responsible for the dryness of the Atacama Desert in northern Chile and the coastal areas of Peru and southern Ecuador.

With the periodic occurrence of the El Niño phenomenon , the cold Humboldt Current weakened with major socio-economic and climatic effects.

See also

literature

  • Aaron Sachs: The Humboldt Current: Nineteenth-Century Exploration and the Roots of American Environmentalism . Penguin, New York City 2007, ISBN 978-0-14-311192-4 .

Individual evidence

  1. Alexander von Humboldt: Kosmos - Draft of a physical description of the world . In: Kosmos . 1st edition. tape 1-5 . Cotta, Stuttgart; Tübingen 1845, urn : nbn: de: kobv: b4-16724-6 .
  2. Penven, P., V. Echevin, J. Pasapera, F. Colas, and J. Tam (2005), Average circulation, seasonal cycle, and mesoscale dynamics of the Peru Current System: A modeling approach, J. Geophys. Res., 110, C10021, doi: 10.1029 / 2005JC002945 .
  3. Barange, M., Bahri, T., Beveridge, MCM, Cochrane, KL, Funge-Smith, S. & Poulain, F., (Eds.): Impacts of climate change on fisheries and aquaculture: synthesis of current knowledge, adaptation and mitigation options. FAO Fisheries and Aquaculture Technical Paper No. 627. 2018. Rome, FAO. 628 pp url