我国北方沙尘天气演变趋势及其气候成因分析  

VARIATION OF DUST WEATHER AND ITS CLIMATIC ATTRIBUTION ANALYSIS IN NORTHERN PART OF CHINA

作　　者：张莉[1] 丁一汇[2] 任国玉[2] 

机构地区：[1]中国气象科学研究院,北京100081 [2]国家气候中心,北京100081

出　　处：《应用气象学报》2005年第5期583-592,共10页Journal of Applied Meteorological Science

基　　金：国家"十五"科技攻关项目课题"全球与中国气候变化的检测和预测"(2001BA611B-01);科技部公益项目"我国西北地区生态气候环境监测;预测方法研究"(WY-2001-02);中国气象局IPCC专项经费;中国气象局国家气候中心气候研究开放实验室开放基金共同资助

摘　　要：利用地面气象观测资料,分析了我国北方1954～2001年年、季沙尘天气发生日数的演变规律及其与主要气候要素,风速、相对湿度、降水、气温和干燥度的相关关系,用NCEP/NCAR再分析资料分析了冬春气压梯度的变化趋势.结果表明:近50年来,造成我国北方沙尘天气频率显著下降的直接自然原因是沙尘源区和发生区平均风速和大风日数的减少、主要沙尘源区降水量特别是春季及其前冬降水量的增加以及由于源区降水增加引起的大气和土壤湿润程度的改善.冬春季节气压梯度的减小是风速减小、进而导致沙尘日数减小的关键间接因素.Based on the surface observations from 1954 to 2001, the tendency of dust weather frequency is presented by Mann-Kendall method, and the relationships of the frequency to wind,relative humidity, air temperature and dryness index are analyzed. The Geopotential height in 1000 hPa from NCEP/NCAR reanalysis data is used to study the pressure gradient change in winter and spring from 1954 to 2001. Results show that the direct natural causes of dust weather frequency change in the recent 50 years include the decrease of daily mean wind speed, the decrease of number of days with daily mean wind speed higher than 5.0 m/s, the increase of precipitation in the same spring and last winter, and the improved condition of atmosphere and soil moisture in some potential dust resource areas. Results also show that decrease of pressure gradient in winter and spring influences dust weather frequency by affecting wind speed indirectly.

关 键 词：沙尘天气 风速 降水 气温 气候变化 气候要素 NCEP/NCAR再分析资料 成因分析 演变趋势 北方 

分 类 号：P425.55[天文地球—大气科学及气象学]