Total inorganic carbon

The total volume of the world s oceans is 1.35 x 1031 1 with a total mass of 1.4 x 1031 kg compared with a fresh water mass of 1.26 x 1017 kg. The pH of the oceans, however, is moderated into layers because the oceans are not well mixed. There are essentially three layers - the surface layer, the mixed layer and the deep layer - and the volume of the mixed layer is 2.7 x 1019 1 to a mean depth of 75 m. The solubility of CO2 enables the precipitation of C032- to be estimated, from which an estimate (although it is fraught with approximations) of the total inorganic carbon in the world s mixed layer is 3.91 x 1016 kg. 

The strong increase in atmospheric concentrations of carbon dioxide [ 127] has generated considerable interest in the global carbon cycle [ 128-130]. Techniques for determining the components of the carbonate system have been refined, new techniques have been developed, or both. Among the four measurable parameters (total inorganic carbon), pH, pC02, and total alkalinity... 

Stoll et al. [142] have described a rapid continuous-flow determination of total inorganic carbon in seawater samples. The method runs on an autoanalyser Traacs 800 spectrophotometric system and is calibrated versus certified reference materials readily available. A typical analysis speed of 45 samples per hour can be reached with an accuracy of 2-3 xM and a precision of 2.5 xM. 

Johnson, K.M., A.G. Dickson, G. Eisheid, C. Goyet, P. Guenther, F.J. Millero, D. Purkerson, C.L. Sabine, R.S. Schottle, D.R.W. Wallace, R.J. Wilke, and C.D. Winn. 1998. Coulo-metric total carbon dioxide analysis for marine studies Assessment of the quality of total inorganic carbon measurements made during the U.S. Indian Ocean C02 survey 1994-1996. Marine Chemistry 63(l-2) 21-37. 

Fig. 38. Estimate of the total inorganic carbon concentration (- -) estimated state, (—) experimental on-line measurements...

Fig. 49. Estimation of the total inorganic carbon concentration (—) upper and lower estimated states, (- -) predictions of the model...

Fig. 58. Total inorganic carbon concentration (—) estimated upper and lower bounds and (o) off-Une readings...

Let us admit that total inorganic carbon represents the summation of partial molalities ... 

Table 8.8 Compositions of superficial and deep waters of the Sarcidano region (Sardinia, Italy) equilibriated with Mesozoic dolomite limestones (Bertorino et ah, 1981). Values in mEq/1. C-j- total inorganic carbon in mmol/1.

From the equation of total inorganic carbon (eq. 8.94), combined with equations 8.97 and 8.99, we derive... 

In the total inorganic carbon balance of equation 8.94, we neglected the presence of some species. Table 8.9 shows that this approximation is reasonable although, for accurate calculations, we should also have considered bicarbonates CaHC03 and MgHCO and the soluble carbonate CaCO . Note also that sulfates occur in negligible molar proportions and that carbonate alkalinity coincides with total alkalinity. 

Total Inorganic Carbon ( xg/g) Total Organic Carbon ( xg/g) Si (Hg/g) Ethanolic Si (Hg/g) Aqueous Extract Metal Concentration in Aqueous Extract ... 

A systematic dependence of reaction order on temperature and pH is not visible, n varies between one and two. Different experimental conditions and/or missing details about these conditions as well as different analytical methods make a comparison of these results impossible. Staehelin and Hoigne (1985) proposed a possible explanation for the second order reaction (n = 2). Since in clean water ozone not only reacts with the hydroxide ions but also with the intermittently produced hydroxyl radicals (see Chapter A 2), it behaves like a promoter and the decay rate increases with the square of the liquid ozone concentration. This is supported by the results obtained by Gottschalk (1997). She found a second order decay rate in deionized water, compared to a first order decay rate in Berlin tap water, which contains about 4 mg L DOC and 4 mmol LT1 total inorganic carbon. Staehelin and Hoigne (1982) also found first order in complex systems. 

Figure 12.2 Observations of total inorganic carbon, nitrate, total inorganic phosphorus, oxygen and H+ in the North Pacific Ocean a ef a/., in prep.). The total inorganic-carbon concentration in this figure is also shown resolved into its components, HCO3, CO and H cal axes here and in subsequent figures give depth in kilometres. Dominant species of each element are shown adjacent to each figure.

Total inorganic carbon TIC All IC present in the form of carbonate, bicarbonate, and dissolved... 

Total C02 is also commonly referred to as total inorganic carbon and... 

From Figure 9.1, it can be seen that the major form of carbon in the atmosphere is C02(g), constituting over 99% of atmospheric carbon. Carbon dioxide makes up 0.035% by volume of atmospheric gases, or 350 ixatm = 350 ppmv. The atmosphere has a mass of CO2 that is only 2% of the mass of total inorganic carbon in the ocean, and both of these carbon masses are small compared to the mass of carbon tied up in sediments and sedimentary rocks. Therefore, small changes in carbon masses in the ocean and sediment reservoirs can substantially alter the CO2 concentration of the atmosphere. Furthermore, there is presently 3 to 4 times more carbon stored on land in living plants and humus than resides in the atmosphere. A decrease in the size of the terrestrial organic carbon reservoir of only 0.1% y-1 would be equivalent to an increase in the annual respiration and decay carbon flux to the atmosphere of nearly 4%. If this carbon were stored in the atmosphere, atmospheric CO2 would increase by 0.4%, or about 1 ppmv y-l. The... 

We used these data for calculation of carbonate system parameters. The calculations were made with a standard set of equations [32], For these calculations we corrected the alkalinity changes for phosphate, ammonia, and sulfide as is recommended for the Black Sea [74]. The results of these calculations revealed the formation of two minima of CO2. A well-pronounced shallower minimum with relative decrease of concentrations by 0.015 mM and a total inorganic carbon (TIC) decrease by 0.040 mM was observed at the density layer = 15.85-15.95 kgm-3, and a smoothed deeper minimum was observed below the sulfide boundary. In the anoxic water the pH slightly decreases down to 75-7.6, and alkalinity increases to 4.50-4.55 mM (Fig. 4). 

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