Cloud-Ensemble Relations Based on the Gamma Probability Distribution for the Higher-Order Models of the Planetary Boundary Layer

Abstract

This paper aims to develop and test a parameterization scheme for partial cloudiness, to be used in the framework of higher-order models of the turbulent planetary boundary layer. The proposed scheme is designed to be general enough and fairly accurate, although slightly at the expense of simplicity. It is based upon the assumption that the total moisture and temperature fluctuations follow gamma probability density functions, which allow for a variable skewness factor, and therefore for different cloud layer regimes. It is nevertheless believed that simpler parameterizations can be used in a number of ways, depending upon specific uses.