The variations of East Asian winter monsoon during the last 40 years period (1951—1990) were studied, the relationship between winter monsoon activities and temperature anomalies in China was examined. The winter monsoon was characterized by two indices: IWS and IWE. IWS represents the intensity of winter monsoon. IWE reflects the extent of southward extension of winter monsoon along the eastern coast of Asian continent. The power spectrum analysis shows 11.0 a and 2.2 a periodicity in the variations of IWS, and 7.3 a and 3.1 a periodicity for IWE, respectively. IWS negatively correlates to the winter temperatures over China except in the south-west highland regions. IWE also negatively correlates with the winter tempertures in China, but significant correlations were concentrated in a region shaped like U capital, which begins from the eastern coast, goes to the south, then turns to the west and goes to the upper reaches of the Changjiang River. But IWE does not always vary parallely to the IWS. For example, the mean anomaly of IWS in 1950’s was positive, but negative for IWE. So, the temperatures were lower in North China, and higher in the U-shape region than the normal in 1950’s. On the contrary, in 1980’s the mean anomaly was negative for IWE, and positive for IWS. Therefore, the general warming covered the whole North China, but the temperatures were relatively low in the U-shape region.
DownLoad: