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Natural Phenomena

Upwelling

Ocean and Marine Phenomena

An oceanographic process in which wind-driven surface currents push warm surface water away from a coastline, allowing colder, nutrient-rich water from the deep ocean to rise and take its place. The nutrients upwelling delivers to the sunlit surface layer fuel some of the ocean's most productive fisheries, including those off the coasts of Peru and California, and a weakening of upwelling during an El Nino event can collapse those fisheries for a season or more.

Facts
Periodicity
Varies by system: some coastal upwelling runs year round (major coastal upwelling systems) while other coastal upwelling happens only in certain months of the year (seasonal coastal upwelling systems). 1
Scale
Globally significant despite a small footprint: about a quarter of the world's total marine fish catch comes from just five major upwelling systems that together cover only about five percent of the ocean's area. 1
Identification
Distinguishing Appearance
A patch of unusually cool, nutrient-rich surface water, identifiable from cool sea surface temperatures and elevated chlorophyll compared to the surrounding ocean. 1
Connections

Demonstrated By

Gulf of California, Ecosystems
Source National Oceanic and Atmospheric Administration
Lake Tanganyika, Ecosystems

Seasonal wind driven upwelling brings nutrient rich deep water to the surface of Lake Tanganyika, sustaining the fisheries that shoreline communities depend on.

Source Encyclopaedia Britannica
Neritic Zone, Biomes
Ross Sea, Ecosystems
Source National Oceanic and Atmospheric Administration
Sources
1. Upwelling (Wikipedia)
Wikimedia Foundation
  • Lead section
    upwelling zones to be identified by cool sea surface temperatures (SST) and high concentrations of chlorophyll a
  • Types, Coastal subsection
    upwelling exists year-round in some regions, known as major coastal upwelling systems, and only in certain months of the year in other regions, known as seasonal coastal upwelling systems
  • Lead section, global fishery statistic
    Approximately 25% of the total global marine fish catches come from five upwellings, which occupy only 5% of the total ocean area.
View the Source
National Oceanic and Atmospheric Administration
National Oceanic and Atmospheric Administration
  • Demonstrated By: Ross Sea
  • Demonstrated By: Gulf of California
View the Source
Encyclopaedia Britannica
Encyclopaedia Britannica, Inc.Demonstrated By: Lake TanganyikaView the Source
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