Carbon cycle models and

GLOBAL CARBON CYCLE MODEL AND NUMERICAL RESULTS... 

Global carbon cycle model and numerical results 199... 

The most common way in which the global carbon budget is calculated and analyzed is through simple diagrammatical or mathematical models. Diagrammatical models usually indicate sizes of reservoirs and fluxes (Figure 1). Most mathematical models use computers to simulate carbon flux between terrestrial ecosystems and the atmosphere, and between oceans and the atmosphere. Existing carbon cycle models are simple, in part, because few parameters can be estimated reliably. 

Budgets and cycles can be considered on very different spatial scales. In this book we concentrate on global, hemispheric and regional scales. The choice of a suitable scale (i.e. the size of the reservoirs), is determined by the goals of the analysis as well as by the homogeneity of the spatial distribution. For example, in carbon cycle models it is reasonable to consider the atmosphere as one reservoir (the concentration of CO2 in the atmosphere is fairly uniform). On the other hand, oceanic carbon content and carbon exchange processes exhibit large spatial variations and it is reasonable to separate the... 

Fig. 11-9 (a) The vertical distributions of alkalinity (Aik) and dissolved inorganic carbon (DIC) in the world oceans. Ocean regions shown are the North Atlantic (NA), South Atlantic (SA), Antarctic (AA), South Indian (SI), North Indian (NI), South Pacific (SP), and North Pacific (NP) oceans. (Modified with permission from T. Takahashi et ah, The alkalinity and total carbon dioxide concentration in the world oceans, in B. Bolin (1981). Carbon Cycle Modelling," pp. 276-277, John Wiley, Chichester.)... 

Bacastow, R. B. and Bjdrkstrom, A. (1981). Comparison of ocean models for the carbon cycle. In "Carbon Cycle Modeling" (B. Bolin, ed.), pp. 29-79. Wiley, New York. 

Kashiwagi, H., Shikazono, N. and Tajika, E. (2000) Global carbon cycle model in the Cenozoic. 10th Annual V.M. Goldschmidt Conference, September 3-8, Oxford University Abst. 

A. W. King, W. R. Emanuel, and W. M. Post, Projecting future concentrations of atmospheric COi with global carbon cycle models the importance of simulating historical changes. Environmental Management /6 91 (1992). 

Siegenthaler, V., and K. O. Miinnich. 1981. 13C/12C fractionation during C02 transfer from air to sea. In Carbon Cycle Modelling. Ed. B. Bolin, New York John Wiley and Sons, pp. 249-57. 

Since the biospheric growth rate depends, among other factors, on the C02 supply, it is probable that the C02 increase induces, at least for part of the biosphere, an increased growth rate ("C02 fertilization"). A simple concept to take this into account is the introduction of a biota growth factor e if the atmospheric C02 pressure increases by p percent, the C02 flux to the biosphere increases by zp percent. Typically, values for e between 0 and 0.5 have been used in carbon cycles models [26,41]. 

Guilderson, T.P., K. Caldeira, and P.B. Duffy. 2000. Radiocarbon as a diagnostic tracer in ocean and carbon cycle modeling. Global Biogeochemical Cycles 14(3) 887-902. 

Kondratyev K.Ya. and Krapivin V.F. (2004a). Global Carbon Cycle Modelling. Science Publ., Moscow, 335 pp. [in Russian]. 

Aumont O, Belviso S, Monfray P (2002) Dimethylsulfonio-propionate (DMSP) and dimethylsulfide (DMS) sea surface distributions simulated from a global three-dimensional ocean carbon cycle model. J Geophys Res-Oceans 107 Article no. 3029... 

Bacastow R. and Keeling C. D., Atmospheric carbon dioxide concentration and the observed airborne fraction. In Carbon Cycle Modelling , B. Bolin, ed. SCOPE Report 16. Wiley, New York, pp. 103-112 (1981). 

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