Carbon speciation ocean

Little is known of the oceanic distribution or speciation of cobalt, because very low concentrations (< 200 pM) make its determination difficult. Laboratory studies indicate that cobalt exists in seawater primarily as the cobalt (II) ion and as the carbonate complex. Organic complexes are not considered important. 

Vertical concentration profiles of (a) temperature, (b) potential density, (c) salinity, (d) O2, (e) % saturation of O2, (f) bicarbonate and TDIC, (g) carbonate alkalinity and total alkalinity, (h) pH, (i) carbonate, ( ) carbon dioxide and carbonic acid concentrations, and (k) carbonate-to-bicarbonate ion concentration ratio. Curves labeled f,p have been corrected for the effects of in-situ temperature and pressure on equilibrium speciation. Curves labeled t, 1 atm have been corrected for the in-situ temperature effect, but not for that caused by pressure. Data from 50°27.5 N, 176°13.8 W in the North Pacific Ocean on June 1966. Source From Culberson, C., and R. M. Pytkowicz (1968). Limnology and Oceanography, 13, 403-417. 

Morse J.W. and Berner R.A. (1979) The chemistry of calcium carbonate in the deep oceans. In Chemical Modelling—Speciation, Sorption, Solubility, and Kinetics in Aqueous Systems (ed. E. Jenne), pp. 499-535. Amer. Chem. Soc., Washington, D.C. 

Physico-chemical speciation refers to the various physical and chemical forms in which an element may exist in the system. In oceanic waters, it is difficult to determine chemical species directly. Whereas some individual species can be analysed, others can only be inferred from thermodynamic equilibrium models as exemplified by the speciation of carbonic acid in Figure 9. Often an element is fractionated into various forms that behave similarly under a given physical (e.g., filtration) or chemical (e.g., ion exchange) operation. The resulting partition of the element is highly dependent upon the procedure utilised, and so known as operationally defined. In the following discussion, speciation will be exemplified with respect to size distribution, complexation characteristics, redox behaviour and methylation reactions. 

Boron has two stable isotopes, 10B and UB, with an average relative abundance of20% and 80%, respectively. The fractionation of 10B/nB (expressed as 8nB, in per mil) relates to boron s speciation as either B(OH), " or B(OH)3j rather than any strong temperature or redox dependence. Most continental (e.g. granitic) rocks, and therefore rivers draining therefrom, have 8nB values close to 0%o, whereas ocean water has a 8nB value of +39%o, due to preferential adsorption of the B(OH)3 species onto marine clays and carbonates. 

Murray RW, Leinen M, Isem AR (1993) Biogenic flux of A1 in the central equatorial Pacific Ocean Evidence for increased productivity during glacial periods. Paleoceanogr 8 651-670 Murray RW, Knowlton C, Leinen M, Mix AC, Polski CH (2000) Export production and carbonate dissolution in the central equatorial Pacific Ocean over the past 1 Ma. Paleoceanogr 15 570-592 Nancollas GH, Amjad Z, Koutsoukas P (1979) Calcium phosphates-speciation, solubility, and kinetic considerations. Am Chem Soc Symp Ser 93 475-497... 

Anthropogenic Trace Elements in the Ocean. Atmospheric Input of Pollutants. Carbon Cycle. Conservative Elements. Hydrothermal Vent Fluids, Chemistry of. Marine Silica Cycle. Metal Pollution. Nitrogen Cycle. Platinum Group Elements and their Isotopes in the Ocean. Refractory Metals. River Inputs. Transition Metals and Heavy Metal Speciation. 

Carbon dioxide and its carbonate minerals play an important role in environmental chemistry and atmospheric physics. In natural waters, atmospheric CO2 has a significant influence on pH, which varies from alkaline seawaters to acidic low mineral lakes, rivers, and soil water. In freshwaters and in oceans the equilibrium relationships between the carbon dioxide, the chemical and biological components, temperature, and the pH are complex functions. Chemical thermodynamics provide quantitative relationships between chemical energy, ionic reactions, solubilities, speciation, pH, and alkalinity. In natural systems these relationships are also complex functions of chemical and biological effects. 

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