Effect of absorption of solar radiation by water of different optical types on convection and heat transfer just under the air–water interface: the case of zero wind speed

A horizontally infinite water layer cooled from above and absorbing solar radiation is considered. Optical water types are classified according to Jerlov (Marine Optics, Scientific, 1976). The convection and the heat transfer are simulated numerically based on the linear equation of state and the time-dependent two-dimensional heat-conduction and Navier–Stokes equations. To take into account the effect of solar radiation, the conventional heat-conduction law for water with a free surface is corrected by introducing a particular function of heat and solar-radiation fluxes. Analytical expressions for this function are fitted.