基于GPCC数据的1901-2010年东北地区降水时空变化

Spatial and Temporal Variations of Precipitation in Northeast China from 1901 to 2010 Based on GPCC Data

基于1901—2010年GPCC[全球降水气候中心(Global Precipitation Climatology Centre)研制的逐月降水格点数据]月降水格点数据与东北地区79个气象站1961—2010年逐月降水资料,利用相关分析、EOF分解、气候倾向率、M-K统计检验和集合经验模态分解(EEMD)等方法,比较了GPCC降水数据与观测数据的差异,探讨了GPCC数据描述的东北地区近百余年不同时间尺度(年、季)降水变化特征。结果表明:1961—2010年GPCC与东北地区站点数据有着非常显著的相关关系,年GPCC降水与站点数据的距平相关系数为0.96,其与同期东北地区79个气象站的平均偏差仅为5.3%,表明GPCC数据对东北地区降水具有非常好的描述性。GPCC描述的1901—2010年东北地区降水是微弱增加的。从主模态来看,GPCC数据描述的东北地区近百年降水在20世纪初到20年代末处于偏少阶段;30年代到60年代东北地区降水显著增加,处于偏多阶段;70年代后降水又有所减少,但在80年代后期和90年代后期出现个别降水偏多年。从季节变化来看,1901—2010年东北地区秋季降水呈现一定的减少趋势,而其他季节降水有所增加。此外,东北地区降水存在年际(3.5,7.3a)、年代际(12.3,26.7a)和百年时间尺度(112.3a)的特征周期变化。

Precipitation is one of the most important part for global energy and water cycle as well as the key problem for study of climate change and variability.However,there are some uncertainties of precipitation change while comparing with the widespread and sustained global warming trend.The results show that precipitation had significant regional differences and decadal variability in recent 50 years of China.Since the late 1970 ssummer precipitation has being decreasing in north China and the Yellow River Basin.But in the middle and lower Yangtze River Basin to south China precipitation is significantly increasing.These factors lead to the spatial pattern of flooding in the south and drought in the north.However,we found that lots of research works for precipitation are limited in recent 50 or 60years because of the length of observed data.Aiming at these problems,domestic and foreign research institutions paid great efforts to create some longer sequence global grid precipitation datasets,and used these datasets to carry out a lot of innovation research.So in this paper,the variation of precipitation was studied from 1901 to 2010in northeast China by using GPCC data.The results indicated that GPCC data showed significant correlation with the station data.GPCC show that the precipitation from 1901 to 2010is slight increasing in northeast China,and it displays similar spatial distribution of precipitation to station data.There are two relative drier periods from 1901 to 2010.The first period is from 1901 to 1930,and the other one is from 1971 to 2010,while the relative wet period is from 1931 to 1970.There is decreasing trend of autumn in 1901—2010,but precipitation is increasing in the other seasons.GPCC data have the annual,decadal and multi-decadal time scales cycle.Finally,we hopethis study can help deepen understanding of the climate change in northeast China,and provide reference for research on climate,ecology and hydrology by using the other relevant data as well.