机构地区: 中国科学院青藏高原研究所
出 处: 《高原气象》 2007年第6期1287-1292,共6页
摘 要: 东亚地区降水主要集中在夏季,是亚洲夏季风系统的重要特征。本文利用NCEP再分析资料和CRU的降水资料,分析了青藏高原非绝热加热对东亚夏季降水的影响。结果表明,东亚地区夏季降水的分布形势与青藏高原非绝热加热变化有很好的相关关系。由于高原非绝热加热可在亚洲东部沿海地区强迫出类似Rossby波列的大气环流低频振荡结构,而此低频波可以影响到西太平洋副热带高压的形态和位置变化,从而使得东亚夏季降水的形势发生变化。而青藏高原非绝热加热的形态从春季到夏季有很好的持续性,春季高原加热与夏季东亚的降水形势分布也有很好的相关。本研究中采用的青藏高原非绝热加热指数可作为东亚夏季降水预测的一个指标,亚洲季风降水不仅受赤道太平洋海温的影响,青藏高原地区的非绝热加热对其也有显著的影响作用。 The feature of East Asian summer precipitation pattern is an important character of Asian summer monsoon. Using the NCEP/NCAR reanalysis data and CRU precipitation data, this study reveals the effect of the Tibetan Plateau (TP) heating on the East Asian summer rainfall. Result shows the close correspondence between TP diabatic heating and East Asian simmer rainfall pattern. The TP heating fluctuation is associated with a Rossby wavelike circulation pattern on the coast area of East Asia. The Rossby wavelike pattern in turn affects and modifies the Northwest Pacific anticyclone, the result causes the varia- tion of East Asian rainfall pattern. Because of the persistent TP diabatic heating from spring to summer and its effect on the surrounding areas, the TP heating index defined in this study can be used as a good predictor for the summer East Asian precipitation distribution. In this work, evidences shown the SST is not an only dominate external condition but also to consider other factor for understanding Asian summer monsoon.
关 键 词: 青藏高原 非绝热加热 东亚降水 亚洲夏季风 大气环流
领 域: [天文地球]