THE MICROPHYSICAL STRUCTURE OF SNOW CLOUD AND THE GROWTH PROCESS OF SNOW IN WINTER IN XINJIANG

The microphysical structure and growth process of snow was observed by means of instrumented aircraft, weather radar,snow crystal observation and others during the winter in 1982 in Ürümqi region. Some preliminary results was obtained, it shows that more than 70% of snow mass growth is produced in the lower cloud under the cold front. In the lower cloud, the ice crystal concentration is as high as 60 per litre, and the supercooled water is absent, so that the diffusional growth of icecrystals and the aggregation of snow crystals are important process for the snow development. The microphysical structure and the function as a seeder clond of snow band aloft near the aerofront are also described.