Carbon uptake

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... 

Changes in surface temperature elsewhere in the globe are likely to have a lesser impact on carbon or DMS production. For example, the warming that a doubling of atmospheric COj could produce in the Southern Ocean has been modelled to lead to decreased carbon uptake, but enhanced biological productivity, due to the temperature effect on phytoplankton growth." This would lead to an approximately 5% increase in DMS production and a lesser increase in CCN. There is thus a negative feedback here, but only of minor impact. 

Small additions of Ce have been shown to have a favourable influence on oxide growth of several Fe-Cr alloys by improving scale adherence and acting as nucleation sites for CrjO, . Levels of Ce as low as 0.024% reduce the carbon uptake of steels in carbonaceous atmospheres by several orders of magnitude. Trace concentrations of As and Sn have been found to improve the breakaway properties of mild and low alloy steels in CO/COj, whereas Cu has been found to be detrimental. ... 

This high availability of materials can also be related to the high enzymatic activities in the water as well as relevant organic carbon uptake by the benthic microorganisms [40, 41],... 

The importance of zinc may extend even further as the processes that control carbon uptake by marine phytoplankton are important in the carbon cycle, and the zinc enzyme carbonic anhydrase could be a limiting factor. The concentration of zinc available to some marine phytoplankton has... 

Large-scale gasification reactor technology based on EF gasification from (a) General Electric (GE Texaco process) and (b) Conoco-Phillips (E-Gas). (Adapted from Meier, D. Faix, O. Fast pyrolysis A route for energy and chemicals from wood—fluidized vs. ablative pyrolysis. In Wood and Biomass Utilization for the Carbon Uptake, Seoul National University, Seoul, 2005, pp. 55-68.)... 

Carbon uptake reduced >40% (DeNoyelles and Kettle 1985) Immediate decline in primary productivity and community metabolism no recovery (Stay et al. 1985)... 

Hamilton, P.B., G.S. Jackson, N.K. Kaushik, and K.R. Solomon. 1987. The impact of atrazine on lake periphyton communities, including carbon uptake dynamics using track autoradiography. Environ. Pollut. 46 83-103. 

Daily additions of 10 pg/L for 8 days reduced algal growth rate and carbon uptake inhibition persisted for 2 18 h and did not affect community composition 2... 

Rnauer, K. and Buffle, J. (2001). Adsorption of fulvic acid on algal surfaces and its effect on carbon uptake, J. Phycol., 37, 47-51. 

The initial decrease in ocean uptake rate will eventually be reversed once enough time has passed (millennia) for meridional overturning circulation to recycle the subsurface waters. This will serve to inject CO2 below the mixed layer. Once the surface waters have been sufficiently acidified and are transported into the deep sea, they will eventually start dissolving sedimentary calcium carbonate. The resupply of alkalinity via this route will provide sufficient enhancement to ocean carbon uptake capacity to... 

The structural effects can also be observed experimentally. Again we illustrate it for the methane activation over Ni surfaces. Figure 4.16 shows that the stepped Ni(211) surface has a considerably lower barrier for dissociation than the flat (111) surface. This has been confirmed in an elegant set of experiments [59]. It turns out that sulfur atoms preferentially adsorb at steps. In this way sulfur can be used to titrate the step sites, and since it also increases the barrier for methane activation considerably (see Figure 4.16), it can be used to block the step sites selectively. Figure 4.18 shows experimental data for the carbon uptake of a Ni(14 13 13) surface... 

Figure 5. A photograph of the fast response ln-sltu CO2 sensor monitoring carbon uptake by a soybean canopy. The open, folded optical absorption cell allows for fast sample exchange. The surrounding instruments measure air flow and humidity variations.

This major input of DOM from macrophytes is not restricted to lakes, but is also realized in other aquatic ecosystems. DOM export from watersheds in lotic ecosystems is directly related to annual runoff, but significantly greater in swamp-draining streams compared with upland-draining streams (Mulholland and Kuenzler, 1979 see Chapter 2 and 6). In the Hudson Estuary, planktonic bacterial production is 3 to 6 times greater than primary production (Findlay et al., 1992). DOC derived from submerged aquatic plants in part supports the difference in bacterial carbon uptake and planktonic primary production. 

The classical studies of Monod (1942) demonstrated a carbon flux partition between catabolism and anabolism, and suggested that a small amount of the carbon uptake is used for maintenance purposes. However, at that time it was impossible to determine the consumption needed for cell maintenance, because the methodologies lacked precision. 

Lucas, W.J., and Berry, J.A. (1985) Inorganic Carbon Uptake by Aquatic Photosynthetic Organisms. American Society of Plant Physiology, Rockville, MD. 

Fe enrichment impacts directly and/or indirectly on the bacterial growth efficiency (BGE), i.e., the ratio between growth and carbon uptake. Nevertheless a different limitation was observed in presence of DOM or TOM. Fe conditions affected bacterial growth efficiency, especially when organic matter was provided in the only dissolved form (Table 4). In... 

Fe has been shown to play a key role in limiting phytoplankton growth and carbon uptake, and in determining the phytoplankton community structure in the Southern Ocean. Therefore, the carbon transfer efficiency to deep water by the biological carbon... 

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