Carbon reservoir concentrations

Fluxes are linear functions of reservoir contents. Reservoir size and the residence time of the carbon in the reservoir are the parameters used in the functions. Between the ocean and the atmosphere and within the ocean, fluxes rates are calculated theoretically using size of the reservoir, surface area of contact between reservoirs, concentration of CO2, partial pressures of CO2, temperature, and solubility as factors. The flux of carbon into the vegetation reservoir is a function of the size of the carbon pool and a fertilization effect of increased CO2 concentration in the atmosphere. Flux from vegetation into the atmosphere is a function of respiration rates estimated by Whittaker and Likens (79) and the decomposition of short-lived organic matter which was assumed to be half of the gross assimilation or equal to the amount transferred to dead organic matter. Carbon in organic matter that decomposes slowly is transferred... 

In turn, the concentration of C02 in the atmosphere depends on the mass of the biosphere and its rate of decay after death, and on the carbonic-anhydrase concentrations in the sea surface. In future predictions of the rate of increase of C02 partial pressure in the atmosphere due to burning fossil fuels, it will be important to include the interaction of the atmospheric C02 with the bio-organic reservoir and the catalyzation of its absorption into the sea by means of the action of carbonic-anhydrase dissolved in sea water, considerations which have not been taken into account in past computations. 

The reservoir gas in a wet gas reservoir has a specific gravity of 1.295, a hydrogen sulfide concentration of 20.9 mole percent, and a carbon dioxide concentration of 44.7 mole percent. Determine a value of z-factor for use at reservoir conditions of 5720 psig and 268°F. 

An idea of the size of carbon supplies in reservoirs is schematically shown in Figure 3.1, as proposed in the work of Bolin and Sukumar (2000). The quantities in this scheme differ widely from the data of other authors (Fierer et al., 2003 Siegenthaler and Sarmiento, 1993). Figure 3.1 summarizes some of the published estimates. Nevertheless, their ratio and order of magnitude coincide in most cases. As can be seen, the maximum supply of carbon is concentrated in the World Ocean. The minimum is in the atmosphere. 

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... 

Variability in the Amount of Carbon in Reservoirs. In addition to variations in the production and distribution of radiocarbon over time and within portions of various carbon reservoirs, variations may result in situations where carbon not in equilibrium with the contemporary standard values is added or removed from any reservoir. Two instances of this are well documented since they occurred within the last century as a result of human intervention. The first is known as the industrial or Suess effect and is caused by the combustion of fossil fuels beginning about 1890, resulting in a depletion of atmospheric activities by about 3% (76). A more recent occurrence has been called the atomic bomb or Libby effect. The detonation of nuclear devices in the atmosphere beginning in 1945 produced large amounts of artificial increasing the radiocarbon concentrations in the atmosphere by more than 100% in the Northern Hemisphere (77). Because of equilibration with the oceans, the levels have been diminishing steadily since the atmospheric testing was terminated by the major nuclear powers except France and the People s Repub-... 

The sedimentary layer of the Earth s crust is the main carbon reservoir. The Cc and Co concentrations in the sedimentary layer are by an order of magnitude higher than in granite and basalt layers of lithosphere. The volume of sedimentary shell is about... 

The 8 C values of cultured B. aculeata are all lower than the 8 C of the DIC in the reservoir water, by amounts ranging from 0.4 to more than 1 Mo. The isotopic offsets are consistently greater for smaller specimens (less than 2 pg per shell, dotted diamonds) than for large specimens (more than 2 p,g per shell, solid diamonds) from the same culture chamber. The 8 C offsets in the culture experiments approach the magnitude of AS C values for live (CellTracker Green, this study (circles)) and Rose Bengal stained (McCorkle et al. (1997) (hexagons)) field specimens. We believe these comparable overall offsets have different explanations pore water microhabitat effects on the field specimens, and carbonate ion concentration effects on the cultured specimens. 

Average DIG and Aik concentrations for the World s Ocean are shown in Figure 5 With an average DIG of 2.35 mmol/kg sea water and the world oceanic volume of 1370 X 10 km, the DIG carbon reservoir is estimated to be 37900 x 10 tons G. The surface waters of the World s ocean contain a minor part of DIG, 700 x 10 tons G. However, these waters play an important role in air-deep water exchange (see above). 

Shew, R. D. 1992. Origin and variability of H2S concentrations in siliciclastic and carbonate reservoirs, Smackover and Norphlet Formations of central and eastern Mississippi. American As.socia-tion of Petroleum Geologists Bulletin, 76, 118. 

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