Biological carbon pump

The biological carbon pump transports carbon from surface waters into the ocean interior when organisms produce organic matter that sinks. Its depth and duration of storage depend on how that matter is transformed and remineralized.

Marine primary production: The production of organic matter by marine organisms, chiefly through photosynthesis and chemosynthesis. Phytoplankton fix the dissolved carbon that begins the pump’s journey.
Ocean stratification: The layering of ocean water by density, usually shaped by temperature and salinity. Stratification separates sunlit production from deeper waters and influences vertical exchange.
Sediment trap: A device that collects sinking particles at a chosen depth in the water column. Trap collections provide direct estimates of particle flux through the ocean.
Solubility pump: The ocean’s uptake and redistribution of carbon dioxide through temperature-dependent gas solubility and circulation. It moves carbon mainly as dissolved inorganic carbon, rather than sinking organic matter.
Ocean carbon sink: The net uptake and storage of carbon by the ocean from the atmosphere or other sources. The biological pump contributes to the ocean’s removal of carbon from surface contact with air.
Phytoplankton: Microscopic photosynthetic organisms that drift in aquatic environments. These surface-water producers convert dissolved inorganic carbon into organic matter.
Euphotic zone: The ocean layer receiving enough sunlight for net photosynthesis. Most pump-producing organic matter is formed in this illuminated surface layer.
Carbon export efficiency: The fraction of surface-produced organic carbon that sinks below a specified depth. This measure compares surface production with carbon exported downward.
Carbonate pump: The biological production and sinking of calcium carbonate shells and skeletons in the ocean. It transports carbon in mineral particles, with effects distinct from organic-carbon export.
Carbon cycle: The movement of carbon among the atmosphere, ocean, land, and living organisms. The pump is one pathway within the global exchange of carbon among reservoirs.

Linked from 41 pages