青藏高原东侧地区夏季气温变化及其可能成因

Variation of Summer Air Temperature on the East Side of Qinghai-Xizang Plateau and Its Probable Causes

应用奇异值分解(SVD)和相关分析方法,研究了青藏高原东侧川渝地区气温变化及其原因。结果表明:夏季川渝地区气温与云量之间主要呈反位相关系,其第一模态代表了它们最主要的耦合特征;热带西太平洋海温偏暖(冷),引起副热带高压系统位置偏北(南),使川渝地区总云量偏少(多),造成川渝地区气温偏高(低)。最后建立了川渝地区夏季气温变化的概念模型,指出热带西太平洋海温异常变化,也是造成青藏高原东侧川渝地区气温变冷的主要原因之一。

Using the Singular Value Decomposition (SVD) technique and correlation method, the variation of air temperature and its forming causes were investigated in Sichuan province and Chongqing city (SC) on the east side of QinghaiXizang Plateau. The result shows that the temperature and cloudiness in SC have mainly anticorrelation in summer. The first mode derived from SVD represent the key coupled features of the air temperature and cloudiness fields. The SST over tropical western Pacific are positive(negative) anomalies, the location of subtropical high system to the north(south), the cloudiness in SC decrease(increase), and resulting in the air temperature in SC are warmer (colder) anomalies. Finally, the conceptual model of variation of air temperature in summer was set up in SC. And it is pointed out that the anomalies of SST over tropical western Pacific is also one of the important reasons for the cooling of air temperature in SC on the east side of QinghaiXizang Plateau in summer.