Model, plankton

A number of current coupled ocean-atmosphere climate models predict that the overturning of the North Atlantic may decrease somewhat under a future warmer climate.While this is not a feature that coupled models deal with well, its direct impact on the ocean s sequestration of carbon would be to cause a significant decline in the carbon that is stored in the deep water. This is a positive feedback, as oceanic carbon uptake would decline. Flowever, the expansion of area populated by the productive cool water plankton, and the associated decline... 

Essentially all organic matter in the ocean is ultimately derived from inorganic starting materials (nutrients) converted by photosynthetic algae into biomass. A generalized model for the production of plankton biomass from nutrients in seawater was presented by Redfield, Ketchum and Richards (1963). The schematic "RKR" equation is given below ... 

Inasmuch as the RKR model is a generalization, specific exceptions should be expected. The most important exceptions relate to growth conditions that can affect the stoichiometry of nutrient incorporation into plankton biomass. During respiration, the... 

Reactors which generate vortex flows (VFs) are common in both planktonic cellular and biofilm reactor applications due to the mixing provided by the VF. The generation of Taylor vortices in Couette cells has been studied by MRM to characterize the dynamics of hydrodynamic instabilities [56], The presence of the coherent flow structures renders the mass transfer coefficient approaches of limited utility, as in the biofilm capillary reactor, due to the inability to incorporate microscale details of the advection field into the mass transfer coefficient model. 

Millard, E.S., E. Halfon, C.K. Minns, and C.C. Charlton. 1993. Effect of primary productivity and vertical mixing on PCB dynamics in planktonic model ecosystems. Environ. Toxicol. Chem. 12 931-946. 

Wolf-Gladrow, D. and Riebesell, U. (1997). Diffusion and reactions in the vicinity of plankton a refined model for inorganic carbon transport, Mar. Chem., 59, 17-34. 

Anderson TR (2005) Plankton functional type modelling running before we can walk J Plankton Res 27 1073-1081... 

Falkowski PG, Katz ME, Knoll AH, Quigg A, Raven JA, Schofield O, Taylor FJR (2004) The evolution of modem eukaryotic phytoplankton. Science 305 354-360 Flynn KJ (2005) Castles built on sand dysfunctionality in plankton models and the inadequacy of dialogue between biologists and modellers. J Plankton Res 27 205-210 Fontana A (2007) Chemistry of oxylipin pathways in marine diatoms. Pure Appl Chem 79 481 490... 

Application of radiolabeled mirex to plants grown in a terrestrial/aquatic laboratory model ecosystem indicated that when the plant leaves were eaten by caterpillars, the aquatic system became contaminated. Mirex was detected in all segments of two aquatic food chains (alga > snail and plankton > daphnia > mosquito > fish) within 33 days. Undegraded mirex contributed to over 98.6, 99.4, 99.6, and 97.9% of the radiolabel in fish, snails, mosquitoes, and algae, respectively. No metabolites of mirex were found in any of the organisms (Francis and Metcalf 1984 Metcalf et al. 1973). 

Gussone N, Eisenhauer A, Heuser A, Dietzel M, Bock B, Bohm E, Spero H, Lea D, Buma J, Nagler, TF (2003) Model for kinetic effects on calcium isotope fractionation (6 Ca) in inorganic aragonite and cultured planktonic foraminifera. Geochim Cosmochim Acta 67 1375-1382 Halicz L, Galy A, Belshaw NS, O Nions RK (1999) High precision measurement of calcium isotopes in carbonates and related materials by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS). J Anal Atom Spectr 14 1835-1838... 

Box models are limited in their ability to show temporal and spatial variability. In the case of the former, rates and reservoir sizes are liable to change over time. For example, plankton distributions tend to fluctuate on a seasonal, and even a daily, basis. Climate change appears to be causing rate and abundance changes over longer time periods, such as decades. This temporal variability is difficxflt to show in the box model format. One approach is to provide a range of values for the rate or reservoir size. Likewise,... 

The model provided in Figure 20.1 is for an ocean basin whose abyssal plains all lie below the CCD. This most closely resembles the conditions in the North Pacific, whereas the rest of the ocean basins have a significant portion of their abyssal plains lying above the CCD, and, hence, contain some calcareous oozes. From a global perspective, calcareous oozes are more abundant than siliceous oozes. This is caused by two phenomena (1) all seawater is undersaturated with respect to opal, whereas all surface waters and 20% of the deep waters are saturated with respect to calcite, and (2) siliceous plankton are dominant only in upwelling areas. 

Similar trends are seen in the C/N ratio of DOM. The C/N ratio of bulk deepwater DOM (18 1) is higher than bulk surface-water DOM (14 1), which is in turn higher than plankton (6.6 1). The radiocarbon and C/N observations gave rise to the two-pool model presented in Figure 23.8 in which surface-water DOM is viewed as an admixture of relatively young labile DOM and a much older refractory pool. The labile pool is effectively restricted to its site of formation in the surfece waters, whereas the refractory pool is persistent enough to spread via advective currents throughout the surface and deep ocean. 

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