Advective flux

An estimate of the advective fluxes (processes 1, 2, and 3) requires knowledge of the concentration of the species in solutions and in the solid... 

The advective flux (mol cm-2 s-1) of component i (Eqn. 20.11) across the left side of the control volume is calculated as,... 

Let us assume no advective flux and the diffusive flux to be proportional to the fraction 1 — p of matrix material... 

The total flux of solute C is the sum of the diffusive and advective fluxes... 

Advection (or convection) is the process by which chemicals are transported by the average (or bulk) water velocity. Thus, the advective flux, is described simply by... 

Advection is generally defined as the displacement of a portion of matter with respect to the point of observation under the influence of force fields (Lerman, 1979). An advection flux g/(sec X cm )] of a material with density p (g/cm ) moving at velocity V (cm/sec) with respect to the point of observation is given by... 

The settling of particles (Eqs. 23-18 and 23-19) is a directed flux (like the advective flux of Eq. 22-2). It is always directed from the water into the sediments (Fig. 23.3a). 

Vertical C02 transport in the ocean is determined by advective fluxes and gravitational sedimentation of dead organic matter (flux Advective transport... 

Acridine char nitrogen, retention as function of burnoff, 307/, 308/ Advection fluxes, calculation, 41-43 Aerosol particle size distribution, molecular clusters, 317 Aerosol scavenging pathway, acetic and formic acid formation, 223 Aerosol species, transformation over the western Atlantic, 52 Aerosol sulfate airborne determination, 298 See also Sulfate... 

Baklanov A, Sprensen JH (2001) Parameterisation of radionuclide deposition in atmospheric long-range transport modelling. Phys Chem Earth (B) 26(10) 787-799 Bott A (1989a) A positive definite advection scheme obtained by non-linear renormalization of the advective fluxes. Mon Weather Rev 117 1006—1015 Bott A (1989b) Reply. Mon Weather Rev 117 2633-2636... 

The offshore advective flux for Si shown in Fig. 17.3 (30 X 10 mol d l) was calculated by difference, based on the total flux of dissolved Si supplied to the shelf system (32 X 10 mol Si d-1), the estimated deltaic burial rate (1-3 x 10 mol Si d ), and the nearshore particulate flux (0.1-0.7 x 10 mol Si d ). This advective flux is in good agreement with the results of Daley (1997), who estimated that 30 x 10 mol d of Si leave the shelf, based on seasonal field data and a multibox model for the shelf. Most of the silicate (94%) supplied to the shelf by external sources appears to be transported to the open ocean in either dissolved or particulate form. Approximately 36% of the Si leaving the outer shelf is in particulate form according to these calculations. Biogenic silica export may have contributed to the lack of closure in the Edmond et al. (1981) silicate budget for the shelf, although deltaic burial also remains as a potentially important sink. 

These stresses are similar to the classical Reynolds stresses that result from time or ensemble averaging of the advection fluxes, but differ in that they are consequences of a spatial averaging and go to zero if the filter width A goes to zero. 

This relation can be solved for the superficial velocity, provided that the density is known from a appropriate EOS. For gas mixtures the ideal gas law is often used, thus the changes in composition is taken into account through the average molecular mass of the mixture. Moreover, the continuity equation can be integrated from the inlet z = 0 to any level z = z, to show that the mass flux is constant in the tube pv ) z = (/W ) in = Constant kg/m s). In particular, this integral relationship is frequently used to simplify the models, calculating the convective/advective flux terms from the known inlet values. 

An estimate of the advective fluxes (processes 1,2, and 3) requires knowledge of the concentration of the species in solution and in the solid particles as well as of the rates of sedimentation and pore water flow. The diffusive type processes 4 and 5 depend on vertical gradients of the concentrations of the species as well as on the diffusivities. In regions where bioturbation occurs, the effective diffusivity in the uppermost centimeters of the sediments can be more than that due to molecular diffusion in the pore water alone (cf. Fig. 4-12). 

Advection Flux of a quantity (e.g. heat, chemical substance) by organized fluid motion (see also Diffusion) Aerobic Conditions involving the presence of oxygen as an oxidizing agent... 

Bott, A., A positive definite advection scheme obtained by nonlinear normalization of the advective fluxes. Mon Weath Rev 117, 1006, 1989... 

The conservation of the mass of a fluid in a velocity field v(x, t) is expressed by Eq. (1.1) for the fluid density (mass per unit of volume) field p(x, t), with 5 = 0. The only process moving the fluid mass is transport by the velocity v, giving the advective flux J = pv. Thus, Eq. (1.1) becomes the continuity equation... 

Thus the advective flux of the power in k space is T(k)dk/dt, and the continuity equation for the power of fluctuations (compare with Eq. (1.1)) will read... 

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