PARAMETRIZATION OF HEAT AND MOISTURE TRANSFER IN THE SOIL-VEGETATION SYSTEM FOR USE IN ATMOSPHERIC GENERAL-CIRCULATION MODELS - 1 - FORMULATION AND SIMULATIONS BASED ON LOCAL OBSERVATIONAL DATA

A locally one-dimensional model of heat and moisture transfer in the s oil is described. The ground surface can be bare, vegetated, or snow-c overed. Primary attention is given to possibly accurate calculation of heat and moisture diffusion, with allowance made for all three states of water and their phase transitions. The model was validated in a st and-alone mode (with observed data used as input parameters) by reprod ucing the soil freezing process and seasonal variations in the soil te mperature and moisture characteristics. A comparative analysis of mode l results and available observational data showed sufficiently high qu ality of the model and a possibility of its use within atmospheric gen eral circulation models.