Turbulent Structure Obtained By Les Modelling Under Strong Shear Conditions.

摘要

This investigation uses two-dimensional (2D) and integrated one-dimensional (1D)cospectra obtained from large-eddy simulation (LES) techniques to investigate along-wind and cross-wind differences in the vertical fluxes (heat, moisture, and momentum) for a over-water cold-air outbreak, conditions with strong wind shear and a large surface buoyancy flux. The cospectra of the along-wind momentum flux will be shown to differ qualitatively from the fluxes of temperature and moisture; in particular, the momentum flux is opposite in sign to that of the mean at larger wavelengths. Strong shear conditions often produce roll vortices within the atmospheric boundary layer (BL) and the presence of roll-like features