Statistical Features of the Cold Waves Invaded China and Their Relation to the Snow Cover Area over the Eurasian Continent

Using the record of cold waves invaded China during the 38 winter half-years from September 1951 through April 1989, statistical features of the cold waves are pantadly, monthly and yearly investigated. The cold waves are divided into three grades, i.e. , severe, strong and moderate. The statistical results are as follows: 1. From the accumulated monthly frequencies it is shown that severe cold waves occur most in November and March, but least in February. 2. Yearly frequences of the strong events of the severe cold waves together with the strong cold waves show obvious interannual variations, in which there are not only 2－5 year oscillations, but also about 20 yearly climatic variations. And, in the last twenty years the strong events tend to gradually decrease. In addition, the relationship between the cold waves invaded China and the winter snow area coved over the Eurasion continent has been preliminarily studied based on digitalizing the cold wave record.