Difference of Two 30 Years Averages and Its Influence on Operational Climatic Analysis

A comparison was made between the two climatic averages of meteorological elements from the old period of 1971~2000 to a new period 1981~2010 of 81 meteorological stations used in Southwestern China climate prediction.The results show the climate in new period is wetter and wormer than that in the old period in most areas,and some elements are especially obvious.The anomaly of an element such as the temperature,precipitation,SST and geopotential height,will be changed because of the different climate state in the two period of 1970s and 2000s.The winter temperature anomaly will be decrease and the summer rainfall anomaly will be increase.The difference of the two averages has certain impacts on the operation of climatic analysis and climatic prediction.