THEORETICAL STUDY OF COLD-AIR DRAINAGE

The formation and characteristics of cold-air drainage are studied in this paper.The terrain is considered as an ideal two-dimensional slope which is infinitely extended in y-direction.In general situations,the regularity of cold-air drainage in temporal and spatial variations is obtained by solving numerically the atmospheric equations of motion,the continuity equation,the thermodynamic equation,the surface thermal balance equation and the soil heat conduction equation.We also test the changes of cold-air drainage with cloudiness,the coefficient of turbulent exchange,slope and its length,and the heat flux and thermal characteristics of soil.The calculated results are in agreement with observations.