长江中下游地区夏季旱涝年际、年代际变化的可能成因研究

STUDY OF INTERDECADAL INTERANNUAL VARIATION OF RAINFALL OVER MID-LOWER REACHES OF CHANGJIANG RIVER AND ITS MECHANISM

  • 摘要: 利用NCAR/NCEP提供的40年再分析资料和英国气象局提供的月平均海温资料及中国气象局整编的160站的降水、西太平洋副高参数资料,分析了长江中下游地区夏季降水在20世纪70年代中期前后的显著变化及其可能原因。结果指出东亚夏季风与中东太平洋海温在1976年之前关系不明显,1976年之后东亚经圈环流与低纬纬圈环流耦合紧密,加强了东亚夏季风与中东太平洋海温的联系。而20世纪70年代中期以后中东太平洋前冬的海温异常通过海洋过程影响次年夏季我国近海地区海温变化,近海海温异常作为热源强迫可以使副高位置偏南强度加强,从而造成我国长江中下游地区夏季降水偏多。

     

    Abstract: Based on the NOAA/NCEP reanalyzed data, SST from the England National Meteorological Bureau, and precipitation data and Subtropical West Pacific High parameters from the National Meteorological Center, the interactions of East-Asian summer monsoon with Mid-east Pacific SSTA are analyzed. The interactions display an inter-decadal variation feature. It is found that the East Asian meridional cell is coupled closely with the low-latitude zonal cell after 1976, which strengthens the association between East-Asian summer monsoon and Mid-east Pacific SSTA. The previous winter SSTA over the Mid-east Pacific affects the offsea SSTA in next summer, as heat sources enforce the Subtropical West Pacific High; as a result, the rainfall over the Mid-lower reaches of the Changjiang River in summer is abundant

     

/

返回文章
返回