Variation of annual precipitation in China is one of the basic problems of climate change research, its relations with the East Asian summer monsoon is the important basis for inference of the ancient East Asian monsoon evolution. Issues of whether precipitation series in a single location can be representative of precipitation change in eastern China,as well as the possibility of using precipitation series in a single location as indices for East Asian summer monsoon, are in need of comprehensive analysis and discussion based on systematically collected meteorological observations and records and a variety of summer monsoon index series. In this paper,the authors use the annual precipitation data from 652 stations over 1951 -2010 in China and 7 East Asian summer monsoon indices and the 1 East Asian winter monsoon index to conduct a number of mathematical and statistical diagnosis and analysis. After discounting the effects of missing records and fewer stations in the earlier part of the period, it was found that during the 60 years of 1951 -2010 there was no significant trend in the national average of annual precipitation curve. However, regional precipitation evolution trends differed: western area precipitation showed a significant increasing trend; over a narrow strip from Sichuan to the Northeast of China a decreasing trend in precipitation was significant; and over the larger area of the Southeast of China most locations displayed no significant trend in precipitation. Cluster analysis can provide more objective classification of precipitation distribution. Based on the cluster analysis of precipitation data from the 554 stations with no missing records during 1961 -2010,14main precipitation regions were identified within China. Precipitation variations differ significantly between the various regions. With the exception of annual precipitation in Xinjiang showing an upward trend,other regions exhibited no apparent trends. Spectral analysis showed that there existed oscillations with the period of 2 -4 years in the average annual precipitation in all 14 regions and the 7 East Asian summer monsoon index series (1961 - 2010). The correlation coefficients between the 7 summer monsoon indices and the average annual precipitation( 1951 -2010 years) of the 14 regions showed that 4 of the summer monsoon indices defined by the sea-land air pressure difference did not have statistically significant correlations with the annual precipitation in the 14 regions. Three indices defined in part or entirely by the subtropical circulation showed significant negative correlation with precipitations in 2 - 3 regions. These summer monsoon indices showed certain predictive power for the annual precipitations over the middle and lower reaches of the Yangtze River and the Northwest regions of China. However, they could not show indication of precipitation variations in other regions or the entire eastern region of China. The relationship between the East Asian summer monsoon and the precipitation in China is very complicated. As far as the annual precipitation variation is concerned, the relationship between the East Asian summer monsoon and precipitation in China is mainly reflected in the distribution of the rain belts and spatial distribution patterns of the precipitation. Thus, the intensity of the East Asian summer monsoon cannot be solely determined by the amount of precipitation. Furthermore, precipitation records of a single station cannot be used to indicate the wet and dry conditions over the entire East China and the intensity of the summer monsoon.
variation of annual precipitation in China, East Asian monsoon, summer monsoon indices, inference of the paleo-monsoon, classification of precipitation regions, cluster analysis
NETL
NSTL
维普
万方数据
