4 for stable stratification and equal to 1 for unstable stratification. The boundary conditions for k and ε read: equation(14a) k=u∗3Cμ3/4+maxB0kd1Cμ3/43/4, equation(14b) ε=u∗3kd1, equation(14c) u∗2=τsρo, equation(14d) B=gρo∂ρ∂TFnρocp+∂ρ∂SFsalt, where d1 is the distance from the boundary to the centre of the nearboundary grid cell, κ von Karman’s constant, u* the friction velocity, τs the wind surface stress and B the buoyancy flux due to net Alectinib cost heat (Fn) and salt (Fsalt) fluxes. In the absence of momentum and buoyancy fluxes, minimum values of k and ε are applied. The constants are discussed
in greater detail in Omstedt & Axell (2003). The initial temperature and salinity conditions for the EMB were taken from January 1958. The temperature and Z VAD FMK salinity were 16.6 ° C and 38.5 PSU respectively, from the surface to a depth of 150 m. Then temperature and salinity changed linearly to 14.1 ° C and 38.7 PSU respectively, at a depth of 600 m. From a depth of 600 m to the bottom, temperature and salinity were set to 14.1 ° C and 38.7 PSU respectively.
The initial conditions for the turbulent model assumed only constant and small values for the turbulent kinetic energy DCLK1 and its dissipation rate. The sensible heat flux Fh is given by equation(15) Fh−CHρacpaWa(Ts−Ta),Fh−CHρacpaWaTs−Ta, where CH is the heat
transfer coefficient and cpa the heat capacity of air. The latent heat flux Fe is calculated as equation(16) Fe=CEρaLeWa(qs−qa),Fe=CEρaLeWaqs−qa, where qs is the specific humidity of air at the sea surface, assumed to be equal to the saturation value at temperature Ts, calculated as equation(17) qs=0.622RsPaexpcq1TsTs+273.15−cq2, where Rs = 611, cq1 = 17.27, cq2 = 35.86, and Pa is the air pressure at the reference level. The specific humidity of air at the reference level qa is accordingly calculated as equation(18) qa=0.622RsRhPaexpcq1TaTa+273.15−cq2, where Rh is the relative humidity (0 ≤ Rh ≤ 1). The heat flux due to net long-wave radiation Fl is given by the difference between the upward and downward propagation of long-wave radiation ( Bodin 1979), according to: equation19) Fl=εsσsTs+273.144−σsTa+273.154a1+a2ea1/21+a3N2, where εs is the emissivity of the sea surface, σs the Stefan-Boltzmann coefficient, and a1, a2 and a3 = 0.68, 0.0036 and 0.18 are constants. Furthermore, Nc is the cloud coverage and ea is the water vapour pressure in the atmosphere, related to qa as follows: equation(20) ea=Pa0.622qa.