upwelling

American  

[uhp-wel-ing] / ʌpˈwɛl ɪŋ /

noun

1. an act or instance of welling up.

   an upwelling of public support; an upwelling of emotion in his voice.

2. Oceanography. the process by which warm, less-dense surface water is drawn away from along a shore by offshore currents and replaced by cold, denser water brought up from the subsurface.

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upwelling Scientific  

/ ŭp-wĕl′ĭng /

1. The rising of cold, usually nutrient-rich waters from the ocean depths to the warmer, sunlit zone at the surface. Upwelling usually occurs in the subtropics along the western continental coasts, where prevailing trade winds drive the surface water away from shore, drawing deeper water upward to take its place. Because of the abundance of krill and other nutrients in the colder waters, these regions are rich feeding grounds for a variety of marine and avian species. Upwelling can also occur in the middle of oceans where cyclonic circulation is relatively permanent or where southern trade winds cross the Equator.

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Etymology

Origin of upwelling

First recorded in 1850–55; upwell + -ing ¹

Example Sentences

Upwelling is when cold, deep ocean water rises to the surface.

From Los Angeles Times • Apr. 16, 2026

Upwelling systems rank among the most biologically productive regions on Earth and play an essential role in supporting global fisheries.

From Science Daily • Nov. 30, 2025

Upwelling occurs when deeper ocean layers, which are already nutrient rich and naturally acidic, move upward toward the shore.

From Science Daily • Nov. 30, 2025

"Upwelling can happen rather suddenly, but some indicators can predict it coming. Therefore, we daily measure the dissolved oxygen, the pH values and the ammonia content in the water," Mr Daniel says.

From BBC • Sep. 21, 2023

Upwelling from his shadowy springs   Sweet waters shake a trembling sound, There flit the hoot-owl's silent wings,   There hath his web the silkworm wound.

From Collected Poems 1901-1918 in Two Volumes Volume II. by De la Mare, Walter