Oceans thermodynamic model

However, the problem of the relationship of the mass of the hydrosphere in the Precambrian and Phanerozoic cannot be solved by developing thermodynamic models. The data of isotope geochemistry may be more promising for a solution of the problem of a steady-state or growing ocean. 

Mel nik, Yu.P., 1972a. Thermodynamic model of the geochemical evolution of the atmosphere and ocean in the Precambrian. Geokhimiya (Geochemistry), 12 1856-1864 (in Russian). Geochem. Int., 1975 (in English). 

Asimow P. D., Hirschmann M. M., and Stolper E. M. (2001) Calculation of peridotite partial melting from thermodynamic models of minerals and melts IV. Adiabatic decompression and the composition and mean properties of mid-ocean ridge basalts. J. Petrol. 42, 963-998. 

McCoUomT. M. and ShockE. L. (1998)Eluid-rockinteractions in the lower oceanic crust thermodynamic models of hydrothermal alteration. J. Geophys. Res. 103, 547—575. 

The oceans, like most natural systems, are not at chemical, thermal, or mechanical equilibrium, but in spite of this, our equilibrium thermodynamic model is quite useful if we know how to apply it. We have shown how it is useful at the ocean surface it... 

The model includes a dynamic thermodynamic sea ice model. The dynamics of sea ice are formulated using viscous-plastic rheology [Hibler (1979)]. The thermodynamics relate changes in sea ice thickness to a balance of radiant, turbulent, and oceanic heat fluxes. The effect of snow accumulation on sea ice is included, along... 

The conditions on Titan, both in the atmosphere and in the oceans, can be investigated using the kinetics and thermodynamics introduced in the modelling of the ISM and the prebiotic Earth, now tuned to the surface temperature and atmospheric temperature conditions on Titan. We have seen previously what happens to reaction rates in the ISM and the atmosphere using the Arrhenius equation but we have not yet extended the concepts of AG and thermodynamics to low temperatures. 

The first part of this chapter used the thermodynamic concept of equilibrium to predict the direction of gas exchange, either into or out of the ocean. This does not provide information on the rates of gas exchange. Despite the importance of gas exchange rates, few direct measurements have been made because of the technical difficulties associated with working at the sea surfece. Instead, rates are generally inferred from mathematical models. The most commonly used ones are described below. These models focus on... 

Hydrate dissociation is of key importance in gas production from natural hydrate reservoirs and in pipeline plug remediation. Hydrate dissociation is an endothermic process in which heat must be supplied externally to break the hydrogen bonds between water molecules and the van der Waals interaction forces between the guest and water molecules of the hydrate lattice to decompose the hydrate to water and gas (e.g., the methane hydrate heat of dissociation is 500 J/gm-water). The different methods that can be used to dissociate a hydrate plug (in the pipeline) or hydrate core (in oceanic or permafrost deposits) are depressurization, thermal stimulation, thermodynamic inhibitor injection, or a combination of these methods. Thermal stimulation and depressurization have been well quantified using laboratory measurements and state-of-the-art models. Chapter 7 describes the application of hydrate dissociation to gas evolution from a hydrate reservoir, while Chapter 8 describes the industrial application of hydrate dissociation. Therefore in this section, discussion is limited to a brief review of the conceptual picture, correlations, and laboratory-scale phenomena of hydrate dissociation. 

In addition to the thermodynamic and kinetic models shown above, which use parameters such as temperature, pressure, and carbon content, three initial detection tools enable initial estimates of hydrates in an ocean geologic setting ... 

A reason that there has been so much controversy associated with the relation between the extent of carbonate dissolution occurring in deep sea sediments and the saturation state of the overlying water is that models for the processes controlling carbonate deposition depend strongly on this relation. Hypotheses have ranged from a nearly "thermodynamic" ocean where the CCD and ACD are close to coincident with calcite and aragonite saturation levels (e.g., Turekian, 1964 Li et... 

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. 

The physical-chemical controls on seawater can be attributed to the effect of composition of the major components on the thermodynamic and kinetics of processes in the oceans. In this chapter I will review the experimental and modeling work that has been done on how the composition of the major components of seawater (Na, Mg... 

Model building is part of all science lovely falsifiable hypotheses are built and then broken on the cold facts. Certain key components are common to all models of life s origins—water (though not necessarily in an ocean aerosols are possible hosts of proto-life) inorganic supplies of thermodynamic drive (i.e., interface settings where two or more different conditions are... 

Circulation models are based on the equations of motion of the geophysical fluid dynamics and on the thermodynamics of seawater. The model area is divided into finite size grid cells. The state of the ocean is described by the velocity, temperature, and salinity in each grid cell, and its time evolution can be computed from the three-dimensional model equations. To reduce the computational demands, the model ocean is usually incompressible and the vertical acceleration is neglected, the latter assumption is known as hydrostatic approximation. This removes sound waves in the ocean from the model solution. In the horizontal equations, the Boussinesq approximation is applied and small density changes are ignored except in the horizontal pressure gradient terms. This implies that such models conserve... 

More elaborate models, including the rheology, and the drift of sea ice have to be applied to describe the formation of different ice classes, transports of sea ice, and a forecast potential for ship navigation. Dynamic-thermodynamic sea ice is applied in three-dimensional models of the Baltic Sea by Haapala and Lepparanta (1996), Meier et al., (1999,2(X)2a,b), Lehmann and Hinrichsen (2000), and Schrum et al. (2003). A comprehensive overview of the theory and application of sea ice drift is given by Lepparanta (2005). Models based on the Flexible Model System (FMS), including the Modular Ocean Model (version 4), may also apply a dynamical ice module (Griffies et al., 2004 Balaji, 2004). 

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