Abstract
The direct numerical simulations (DNSs) of neutrally and stably stratified turbulent Ekman layer over a smooth surface are performed using the Boussinesq approximation to account for the buoyancy effect The Reynolds number based on the geostrophic wind, the Ekman layer depth and the kinematic viscosity is 410, which is almost equal to that of Coleman et al (1990) The Grashof number is set to be Gr=0, 3.15×10^6, 6.30×10^6 and 3.15×10^7. A temperature field is so introduced that its mean profile is unchanged with time advancement. As the result, statistical quantities are obtained for both velocity and temperature fields The effects of stable stratification upon the direction of the mean velocity, the Reynolds stress and the turbulent heat flux are discussed based on the obtained DNS data.
