The importance of a high spatial resolution in the Mike 3fm model is not so pronounced, since this model is used only to analyse the dynamics of T, S, σt and their vertical distribution, not for modelling effluent spreading in the near or far field. Therefore, the results of Mike 3fm simulations, for the domain shown in Figure 2, were used only as ‘input’ for the near-field model. The near-field effluent transport model is defined using set of differential equations for motion on steady control volume (Featherstone 1984). The core of the model assumes an initial effluent inflow through a

KU57788 circular nozzle and a single buoyant jet or plume propagation not interacting with any other buoyant jets or plumes from adjacent nozzles. Volume flux ϕ, mass flux Ψ, specific momentum

flux M, buoyancy flux B and specific buoyant force per unit length of a plume T are expressed by integral (1a,b,c) and (1d,e), where A represents the cross-sectional area of a plume orthogonal to the central trajectory, u is the velocity in ABT-263 purchase the plume cross-section, ρ the density in the plume cross-section, Δρ the density deficit (Δρ = ρm – ρ), ρm the sea water density and ρm0 the sea water density at the positions of the diffuser nozzles. equation(1a,b,c) ϕ=∫AudA,ψ=∫AρudA,M=∫Au2dA, equation(1d,e) B=g∫A(Δρρm0)udA,T=g∫A(Δρρm0)dA. The core of the model is contained in the definition of the rate of change for fields ϕ, Ψ, M and B along the central trajectory path s of the stationary plume. Neglecting the influence of the ambient current on the overall plume dynamic, the specific momentum rate of change becomes zero in the horizontal direction ( eq. (2a)). The change in the specific momentum in the vertical direction is caused by buoyancy ( eq. (2b)). As a result of ambient fluid entrainment through the outer contour of the plume, volume flux and mass flux change

Ureohydrolase along path s are defined by equation (3) (Turner 1986). Henceforth, the specific momentum and volume flux follow: equation(2a,b) dds(Mcosθ)=0,dds(Msinθ)=T, equation(3) dϕds=E=2πb αu(s),where u(s) = u(s, r = 0) is the velocity along the central trajectory of the plume, b is the radial distance from the central trajectory to the position where the velocity takes the value of u(s, r = b) = u(s, r = 0)/e, α = 0.083 is the entrainment constant ( Featherstone 1984), and θ is the angle of inclination of the tangent of the plume trajectory to the horizontal axis. One assumes a Gaussian distribution of the velocity u(s, r) and density deficit Δρ(s, r) in the plume cross-section, where the constant λ = 1.16 in the case of scalar transport. equation(4a,b) u(s,r)=u(s)e−r2/b2,Δρ(s,r)=Δρ(s)e−r2/(λb2). Integration of equation (1) (eq. (5)) and definition of the proportionality between dB/ds and ϕ ( eq.