A model for the turbulent structure of the stratocumulus-topped atmospheric boundary layer.

Abstract

Turbulence closure is formulated by using an equation for the turbulent kinetic energy and either a diagnostic formulation of the integral length scale or a parameterized version of the dissipation equation. The latter 2 options are compared. The model is used to study various combinations of physical processes in a cloud-topped ABL and their combined effect on the turbulent structure. The physical processes considered are an upward buoyancy flux at the surface, longwave radiative cooling near cloud top, shortwave radiative heating in the cloud, and wind shear near cloud top. The pronounced differences in the observed turbulent structure of the ABL in these 2 cases (due to different combinations of physical processes) are well simulated by the model.-from Authors