青藏高原地表温度对华北汛期降水变化的影响

利用1980-2001年青藏高原月平均地表温度、1961～2001年我国160站月降水以及NECP／NCAR再分析月平均高度场资料，分析了华北地区汛期降水与青藏高原地表温度的关系，结果表明华北地区汛期降水与青藏高原5～6月地表温度具有显著的正相关。相关场的正值中心位于高原的东北部和西南部地区。华北地区汛期降水偏少年，青藏高原前期5～6月地温以负距平为主且距平值较小；相反，降水偏多年，青藏高原前期5～6月地温以正距平为主且距平值较大。EOF和SVD分析表明，青藏高原5～6月地温和华北地区汛期降水的第一典型场都表现出大体一致的变化特点。此外，诊断分析得到，青藏高原5～6月地温偏高年，7～8月西太平洋副热带高压的强度偏强，位置偏北；地温偏低年，西太平洋副热带高压的强度偏弱，位置偏南。

THE EFFECTS OF TIBETAN PLATEAU SURFACE TEMPERATURE ON THE PRECIPITATION OVER NORTH CHINA DURING RAINY SEASON

The relationship between the rainfall during rainy season over North China and the surface temperature over Tibetan Plateau is analyzed by virtue of the monthly surface temperature over Tibetan Plateau from 1980 to 2001,Monthly NCEP/NCAR reanalysis geopotential height and precipitation at 160 stations of North China from 1961 to 2001.The results show that the notable interrelation is present in the relationship between rainfall during rainy season over North China and the surface temperature during May and June over Tibetan Plateau.The positive center of interrelation fields is located in Northeast and Southwest in Tibetan Plateau.The negative anomaly occupies a dominant position with minor absolute value for drought rainy season over North China,in contrast,the positive anomaly is principal with larger value for flood rainy season over North China.The analyses by EOF and SVD methods indicate that the first pairs of singular grounds of Tibetan Plateau's surface temperature during May and June and the precipitation during rainy season over North China display roughly consistent anomaly change.Furthermore,the diagnostic results present that West Pacific Subtropical High goes stronger and is situated in the northern side during rainy season over North China when the surface temperature over Tibetan Plateau during May and June becomes higher,the opposite is true when the surface temperature over Tibetan Plateau during May and June becomes lower.