thermocline: Quick Facts

Written and fact-checked by

The Information Architects of Encyclopaedia Britannica

Photos

Two diagrams compare coastal upwelling during normal conditions and an El Nino event. The top shows strong upwelling with nutrient-rich water and high plankton near the coast, while the bottom shows weak upwelling, a thicker nutrient-poor surface layer, and reduced plankton during El Nino.

See All Images →

Topics

seawater water mass halocline pycnocline sea ice saltwater intrusion salinity Why Is the Ocean Salty?Why Is There Fresh and Salt Water on Earth?

water glass on white background. (drink; clear; clean water; liquid)

Water and its Varying Forms