Statistical theory of precipitation process

The present article summarizes the research work on cloud physics in the Institute of Geophysics and Meteorology, Academia Sinica, which began only in 1960. In recent years we set forward the statistical theory of precipitation process on the basis of analysing data of cloud microstructure observed in our country. This theory shows that water content and air current etc. in the cloud all undergo great fluctuations and the process of growth of cloud drops is stochastic in a fluctuating environment, which can only be tackled by the methods of probability. This paper presents the general method of statistical theory of precipitation process, discusses the questions on the precipitation from thin clouds and the formation of hail etc., and gives better results which agree closer with actual conditions than those of earlier theoretical calculations.