摘要
论文利用NCEP／NCAR再分析资料及中国142个测站12小时降水资料，采用线性倾向估计、合成分析、相关分析等方法，对青藏高原夏季500hPa纬向风的昼夜变化特征及其影响进行了分析。结果表明：自1950年以来，高原夏季500hPa昼、夜纬向风均呈现整体减弱趋势，且减弱趋势夜间比白天明显，纬向风日较差呈增大趋势。高原昼、夜纬向风在1967年均存在减弱突变，纬向风日较差存在1965年的减小突变和1975年的增大突变，纬向风日较差具有4-6a及16～23a的显著周期。高原昼夜纬向风异常，使得高原东侧及其以东地区出现异常的上升或下沉气流，且高原纬向风减弱时，长江以北的我国大部分地区降水偏少，长江以南地区降水偏多，降水对高原纬向风异常响应的昼夜差异主要表现在四川盆地东西部降水异常的昼夜差异上。
Using the linear-trend estimate, composition and correlation analysis, the diurnal variability of the 500 hPa zonal wind in summer over the Tibetan Plateau and its impact are examined, based on the NCAR/NCEP reanalysis and the twice-daily precipitation data from 142 stations in China. The results reveal that： 500 hPa zonal wind at day and night in summer over the Tibetan Plateau overall show a decreasing trend since 1950, and it is more notable at night. The daily range of zonal wind show a decreasing trend. Zonal winds at day and night over the Tibetan Plateau all have a pronounced abrupt weakening occuring in 1967. The diurnal changes of zonal wind over the Tibetan Plateau have pronounced abrupt reduction occuring in 1965 and greater occuring in 1975. The diurnal change of zonal wind presents the periods about 4 - 6 years and 16 - 23 years. When the zonal wind is abnormal, anomalous ascending or descending flow are found at the east flank of the plateau and areas east of it. When the zonal wind decreases, less precipitation happens in areas north of the Yangtze River, while more precipitation happens in areas south of it. The diurnal variation of response of precipitation to anomalous zonal wind over the Tibetan Plateau is mainly in diurnal variation of the anomalous precipitation over the eastern and the western Sichuan Basin.
出处
《自然资源学报》
CSSCI
CSCD
北大核心
2014年第1期117-128,共12页
Journal of Natural Resources
基金
国家自然科学基金面上项目(41275079)
四川省青年科技基金项目(2012JQ0062)
成都信息工程学院校选项目(CRF201201)
关键词
气候变化
纬向风
昼夜差异
青藏高原
环流
降水
climatic variation
zonal wind
diurnal variation
Tibetan Plateau
circulation
precipitation
