摘要
采用中国160站降水资料、NOAA ERSST海温资料以及ERA-40大气再分析资料,分析了中国东部夏季降水型的年代际变化特征及其与北太平洋海温的可能联系。结果表明:中国东部夏季降水型在近50年中经历了两次年代际变化,第1次发生在20世纪70年代中后期,北太平洋中纬度地区冬季海温由正距平向负距平转变,太平洋年代际振荡(PDO,Pacific decadal oscillation)由负位相向正位相转变,通过影响东亚夏季风环流,使东亚夏季风减弱,中国东部夏季降水从北到南呈现出"+-+"转变为"-+-"的三极分布形态,这次年代际变化体现了同一模态正负位相的转变;第2次发生在20世纪80年代末90年代初,北太平洋海温转变为日本以南西北太平洋的正距平分布,同时菲律宾群岛附近海温偏暖,西太平洋副热带高压偏南偏西,使得中国东部夏季降水由北至南转变成"-+"的偶极分布形态,这次年代际变化体现了一种模态向另一种模态的转变。
By use of monthly precipitation at 160 stations over China, ERA-40 reanalysis data and NOAA ERSST extend-reconstructed global sea surface temperature data, the authors find that the precipitation pattern over eastern China experiences two interdecadal variation processes in recent 50 years, and has close relation to interdecadal vari- ation of the North Pacific SST. In the interdecadal variation process of the mid- and late-1970s, the precipitation pattern form north to south over eastern China changes from ＂＋- ＋＂ to ＂-＋-＂ tripole distributions, and has close relation to the PDO （Pacific decadal oscillation） phase, with SST anomaly from positive to negative in the mid- latitude area of the North Pacific. East Asian summer monsoon circulation is a main bridge of PDO influencing the precipitation pattern. In the interdecadal variation process of the late 1980s and early 1990s, the precipitation pat- tern changes from ＂＋＂ tripole to ＂-＋＂ dipole distributions, and has close relation to higher SST from the northwestern Pacific to the south of Japan and round the Philippines. The first interdecadal variation shows that the same mode changes from one phase to another, and the second one exhibits the changes between different modes.
出处
《大气科学》
CSCD
北大核心
2009年第4期835-846,共12页
Chinese Journal of Atmospheric Sciences
基金
国家自然科学基金资助项目40775059
江苏省普通高校研究生科研创新计划项目CX07B_044z
中国气象局气候研究开放实验室开放课题LCS-2006-09
江苏省高校自然科学基础研究项目07KJ170067
江苏省气象灾害重点实验室课题KLME060302
KLME050104
关键词
中国东部
夏季降水型
北太平洋海温
年代际变化
eastern China, summer precipitation pattern, North Pacific sea surface temperature, interdecadal variation
