Oceanic biological pump

Figure 5.3. Schematic representation of the ocean biological pump. From Usbeck (1999).

Estuaries and the mouths of large river systems are located at an important interface between land and ocean where terrestrially derived materials can be altered before entering continental shelves. Continental shelves provide an estimated net CO2 sink of 0.1 Pg C y 1 (lPg = 1015g), with an export that may be as much as 20% of the oceanic biological pump (Liu et al., 2000). Unfortunately, ocean margins have only recently started to receive the appropriate attention they deserve in the context of their importance in the global C budget (Bauer and Druffel, 1998 Liu et al., 2000) (more details on this in chapter 16). 

Anderson RF, Chase Z, Fleisher MQ, Sachs JP (2002) The Southern Ocean s biological pump during the last glacial maximnm. Deep-Sea Research 1149 1909-1938 Anderson RF, Fleisher MQ, Kubik P (2001) Boimdary scavenging in the North Atlantic ocean. EOS Trans AGU (Fall Meeting Snpplement) OS21D-11... 

Much of the trace metal demand of plankton in the open ocean may be supplied by the aeolian transport of dust. If trace metals limit plankton growth, the factors that control the transport of dust will also ultimately control the ocean s biological pump and, hence, atmospheric CO2 levels. This suggests the existence of powerful feedbacks among the processes that control global climate. For example, shifts in climate that lead to regional... 

The export of DOC into the middle and bottom waters of the ocean represents 20% of the total annual export of carbon from the surfece waters. Thus, DOC export represents a significant part of the biological pump contributing to the ocean s ability to extract and store atmospheric carbon. This export also has ramifications on nutrient... 

Zonally integrated giobai sea-air exchange fluxes for CO2 (positive fluxes denote outgassing from the ocean), (a) Effects of the gas exchange pump and the biological pumps (preindustrial). 

The future response of the ocean to increasing injection of anthropogenic carbon into the atmosphere can be predicted by considering how the physical and biological pumps are most likely to respond. Initially, the physical fectors will lead to a decrease in the ocean s uptake rate. This is a result of four fectors. First, as discussed in Chapter 25.3.1,... 

Biological pump The transport of chemicals in the ocean as a result of incorporation into biological hard and soft parts, followed by pelagic sedimentation into the deep sea. 

Atmosphere-ocean carbon exchange is much controlled by physical processes, including mixing of the surface and deep layers of the ocean across the thermo-cline. Biological processes favor the movement of carbon from the surface layer to deep layers and down to bottom sediments. The biological pump functions as a result of phytoplankton photosynthesis. 

Longhurst, A.R. and Harrison, W.G., The biological pump profiles of plankton production and consumption in the upper ocean, Prog. Oceanogr., 22, 47, 1989. 

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