The Humboldt Current System (HCS) is one of the most productive marine ecosystems on earth. It extends along the west coast of South America from southern Chile (~42 ° S) up to Ecuador and the Galapagos Islands near the equator. The general oceanography of the HCS is characterized by a predominant northward flow of surface waters of subantarctic origin and by strong upwelling of cool nutrient-rich subsurface waters of equatorial origin.
Along the coast of northern and central Chile, upwelling is localized and its occurrence changes from being mostly continuous (aseasonal) in northern Chile to a more seasonal pattern in southern-central Chile. Several important upwelling centres along the Chilean coast are interspersed with long stretches of coast without or with sporadic and less intense upwelling. Large-scale climatic phenomena (El Niño Southern Oscillation, ENSO) are superimposed onto this regional pattern, which results in a high spatiotemporal heterogeneity, complicating the prediction of ecological processes along the Chilean coast.
Source: (PDF) The Humboldt Current System of Northern and Central Chile. Available from: https://www.researchgate.net/publication/210779714_The_Humboldt_Current_System_of_Northern_and_Central_Chile [accessed Nov 08 2018].