A simple parameterization of cloud water related variables for use in boundary layer models

Abstract

A simple parameterisation of cloud water related variables has been developed, which can be used in meteorological models that use a prognostic equation for the turbulent kinetic energy. Based on the results of large-eddy simulations (LES), expressions are derived for the liquid water flux, the partial cloudiness, and the cloud water content as a function of the normalized saturation deficit. With these relations, which are based on LESs ranging from situations with small to moderate amount of cumulus clouds to a stratocumulus case, no further knowledge about distribution functions or skewness is needed. -Authors