Oceanic carbonate system

The committee acknowledges that the particulate flux of carbon out of the euphotic zone, the transformation of particles, and sedimentation and diagenesis on the seafloor are important processes that need to be understood for a full characterization of the ocean carbon system. However, the focus on dissolved analytes was selected because one objective of this report is to interest analytical chemists in applying their techniques to ocean studies. Furthermore, some of the sensor techniques discussed in this report may be modified and engineered for in situ measurements of dissolved species in pore waters of sediments. 

Each GCC model differs in the set of assumptions made and therefore concentrates on different effects. For instance, a simple numerical model of the gas exchange at the ocean-atmosphere boundary in the case of wind-driven roughness of the sea at wind speeds of 7 m s 1 makes it possible to formulate, in the global model, a unit to calculate the persistent C02 flux between the water surface and the atmosphere. This can be exemplified by models of the ocean carbonate system described by many authors. Also, there are other models of the C02 cycle in natural systems (Riedo et al., 2000 Zonneveld, 1998). 

On the whole, when synthesizing a global model of the C02 biogeochemical cycle, the unit to simulate that part of the cycle spent in the ocean must describe how the ocean carbonate system works. Alekseev et al. (1992), analyzing the system C02 IICO, COj and the distribution of pH values in ocean waters, discovered that more than 80% of dissolved carbon dioxide is in the form of hydrocarbonate ion of HC03. This means that when synthesizing a model of the ocean carbonate system only the first stage of the dissociation of carbonic acid can be reliably considered. As a result, the flux of C02 dissolved in the upper layer of the ocean can be calculated by the formula... 

According to Bjorkstrom (1979), the functional dependence of pc on parameters of the ocean carbonate system can be presented in the form pc = [CO2]/A0. From the condition of chemical equilibrium, according to (3.4) and (3.5), it follows that... 

The partial pressure of C02 dissolved in surface waters is proportional to its concentration in the water and inversely proportional to its solubility. This dependence is established by solving the system of Equations (3.12) and (3.13), which describe the functioning of the ocean carbonate system. For the quantitative solution of this system we can use, for instance, the secant method. As a result, we obtain [C02] and P . Based on data on the temperature dependence of the equilibrium constants for the respective chemical reactions, we find ... 

The optimistic scenario of Bjorkstrom (1979) takes into account the ocean-carbonate system by parameterizing the H2 and 7/3 flows in Figure 3.3. 

A major portion of the studies on calcium carbonate reaction kinetics has been done in seawater because of the many significant geochemical problems related to this system. Morse and Berner (1979) summarized the work on carbonate dissolution kinetics in seawater and their application to the oceanic carbonate system. The only major seawater component in addition to Mg2+ that has been identified as a dissolution inhibitor is SO42- (Sjoberg, 1978 Mucci et al., 1989). Sjoberg s studies of other major and minor components (Sr2+, H3BO3, F-) showed no measurable influence on dissolution rates. Morse and Berner (1979) and Sjoberg (1978) found that for near-equilibrium dissolution in phosphate-free seawater, the dissolution rate could be described as ... 

The Oceanic Carbonate System and Calcium Carbonate Accumulation in Deep Sea Sediments... 

Before proceeding with an examination of the oceanic carbonate system and the accumulation of calcium carbonate in deep sea sediments, it is useful to consider briefly the general relationships among the different components and their most basic characteristics. The various components of first order importance to the system are shown in Figure 4.1. These can be divided into external components,... 

The Impact of Fossil Fuel CO2 on the Ocean-Carbonate System... 

Betzer P.R., Byrne R.H., Acker J.G., Lewis C.S., Jolley R.R. and Feely R.A. (1986) Biogenic input to the oceanic carbonate system Mass fluxes of pteropods and foraminifera in tropical, temperate, and sub-arctic regions of the western North Pacific, (manuscript). 

We can now use the knowledge of the Revelle factor to estimate the anthropogenic GO2 uptake by the ocean at equilibrium. Presuming that after some reasonable time the ocean carbonate system comes into equilibrium or nearly so with GO2 in the atmosphere, we can calculate the fraction of the anthropogenic GO2 taken up by the ocean as a function of the depth of the layer into which... 

Bijma, J., Spero, H. J. Lea, D. W. 1999. Reassessing foraminiferal stable isotope geochemistry impact of the oceanic carbonate system (experimental results). In-. Fischer, G. Wefer, G. (eds) Use of Proxies in Paleoceanography Examples from the South Atlantic, Springer-Verlag, BerUn, 489-512. 

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