中国西北春季降水与太平洋海温相关特征的研究

THE CORRELATION BETWEEN THE PACIFIC SEA SURFACE TEMPERATURE (SST) AND PRECIPITATION OVER NW CHINA

应用奇异值分解对中国西北3～5月的降水资料与太平洋海温进行了相关分析。结果表明:北太平洋与中国西北春季降水有较好的相关,在太平洋海温3～5月呈El Nino峰值位相时,除青海高原外,中国西北地区降水偏少;而当12～2月的海温呈El Nino成熟位相型时,次年西北地区3～5月的降水偏多;而当北太平洋海温12～2月呈La Nina型时,次年青海高原区3～5月的降水偏少。太平洋海温的西风漂流区、黑潮区、加利福尼亚海流区和北赤道海流区的海温的变化与中国西北地区3～5月的降水之间有明显的相关关系。其中黑潮区12～2月的海温与新疆北部的降水呈反相变化,即当黑潮区的海温低时,西北地区的新疆北部降水偏多。中国西北地区3～5月的降水对太平洋海温变化的响应区主要是新疆北部、青海高原及其东北侧、沙漠盆地、河西西部等地。

The correlation feature between the Pacific sea surface temperature (SST) and precipitation of Northwest China are analyzed by SVD in this paper. The results show that the precipitation of northwest China is wet when ENSO is developed(March ~ May) , but drought at the ENSO peak(December ~ February), precipitation of North of Xingjiang in Northwest China changes out-of phase with sea surface temperature in the Kuroshio current area. The result of Student抯 搕?test shows that the precipitation over NW China in the year following El Nino is strongly different from that in the years of non-El-Nino. But no significat difference is found in El-Nino years.