近50年东北地区的气候变化事实检测分析

采用国家基准气候站和基本气象站的地面资料,系统地分析了中国东北地区1956年以来近地表主要气候要素演化的时间和空间特征。结果表明:东北近50 a来年平均气温变暖幅度约为1.5℃,增温速率接近0.3℃/(10 a),比北半球和全国同期平均增温速率明显偏高。气温增暖主要发生在最近的20余年。1956年以来东北平均降水量呈略减少趋势,降水变化的空间特征明显而相对稳定,黑龙江的漠河、内蒙古的海拉尔、赤峰的个别地区呈略增加以外,其他大部地区呈减少趋势,尤其黑龙江东部、吉林西部以及辽宁东南部地区降水减少明显。在降水量减少的同时,降水日数也同时减少。分析还发现,近50 a来东北平均的日照时数、平均风速、蒸发量、相对湿度等气候要素均呈显著下降趋势。各不同的气候要素都存在着年际和年代际变化振荡周期,对这些气候要素进行了突变检测,发现年平均气温在1988年发生了明显突变,气温突变首先是以最低气温突变开始的,说明气候变暖是以最低气温变暖开始的。降水量在1961年发生突变,降水量由多减少;降水日数在1994年发生了由多转少的突变;日照时数突变发生在1978年,之后日照时数呈变少趋势。

Climate change of the Northeast China over the past 50 years

A data set of mean temperature,precipitation and other climate parameters for 103 stations was used to analyze the climate change in Northeast China.The data set has been processed more carefully.Analyses have been made for annual mean temperature,precipitation,evaporation,sunshine duration,wind speed,and the relative humidity by using some climatic statistical method.The analyses showed that annual mean surface air temperature in Northeast China as a whole rose by about 1.5 ℃for the last 50 years,with a warming rate of about 0.30 ℃/ 10 a.The warming in the later half 20th century was more rapid than the average values of the Northern Hemisphere and the mainland of China.The most evident warming occurred in winter and spring as expected.A long term slight decreasing trend of averaged annual precipitation was seen in the past 50 years in Northeast China,meanwhile the days of precipitation was decreasing.Annual mean precipitation of most parts in Northeast China decreased,especially the largest drop in precipitation occurred in the east of Heilongjiang Province,the west of Jilin province,the southeast of Liaoning province,however,an slight wetting trend in some places,such as Mohe,Hailaer and Chifeng city.Since 1956,the averaged sunshine duration,evaporation,wing speed and relative humidity have had a significant trend to decrease.Interannual and interdecadal changes of all climate parameters were analyzed,and Mann-Kendall method was used to test the climatic abrupt change.The abrupt change point of annual mean temperature occurred in 1988.The climatic abrupt change of annual mean minimum temperature began earlier than maximum temperature.For precipitation,precipitation days and sunshine duration,the climatic abrupt change points were in 1961,1994 and 1978;after abruptness the trend of these climate parameters decreased.