A THREE-DIMENSIONAL, SECOND-ORDER CLOSURE NUMERICAL MODEL OF MESOSCALE CIRCULATIONS IN THE LOWER ATMOSPHERE:Description of the Basic Model and an Application to the Simulation of the Environmental Effects of a Large Cooling Pond

摘要

This report presents a detailed description of a three-dimensional, mesoscale model of circulations in the lowest few kilometers of the atmosphere', the planetary boundary layer. The model is termed a turbulence second-moment closure model since it is based on various second-moment turbulence equations involving wind velocity, temperature, water vapor, and liquid water.nA simplified version of the model, in which only time-dependent, partial-differential equations for the turbulence energy balance and a master length scale are solved, is recommended. A Gaussian probability function for cloud cover statistics recently proposed (Sommeria and Deardorff, 1977;Mellor, 1977) is used in order to model condensation processes.