摘要
根据中国160站月平均降水、NCEP／NCAR的再分析资料以及英国气象局哈德莱中心1900~1999年全球1°×1°格点月平均海表温度距平资料，利用物理量诊断、EOF分析等方法，探讨东亚季风区大气环流内部动力过程与大气外强迫因子（海温）年代际变化及对中国夏季降水型的影响。分析发现，中国东部地区、西北地区夏季降水型有各自不同的年代际变化趋势；中国东部夏季降水型及东亚夏季风环流年代际变化趋势与大气外强迫因子北太平洋中纬度海温年代际变化（PDO）关系密切；中国西北地区夏季降水年代际变化与大气内部动力过程中纬度西风带扰动动能年代际减弱有关。
Analyses of the monthly precipitation of 160 stations over China during 1951 - 2006, 50-yr NCEP/NCAR reanalysis dataset and monthly 1°× 1° sea surface temperature data of Hadley center during 1900- 1999 reveal remarkably different interdecadal variation of precipitation pattern between eastern and northwestern China in their temporal- spatial distributions. Since the early 1980s the precipitation over the Yangtze River valley became more than climatic average and the precipitation over Huabei Plain became less than climatic average, and since the late 1980s the precipitation over northwestern China became more than climatic average. The contributions of the atmospheric internal dynamic processes and the extra-forcing factors （such as sea surface temperature） to the interdecadal variations of precipitation between eastern and northwestern China are different. The interdecadal variations of pre-cipitation over eastern China during summer are related to the temporal evolution of the Pacific Decadal Oscillation （PDO） by using empirical orthogonal function （EOF） method and regress analysis. The interdecadal variations of precipitation over northwestern China during boreal summer are related to the interdecadal variation of anomalous perturbation kinetic energy of Rossby wave along East Asian westerly jet in mid-latitudes. Since 1988 the perturbation kinetic energy of Rossby wave along East Asian westerly jet in mid-latitudes became weaker and meantime the precipitation over northwestern China became more than climatic average.
出处
《大气科学》
CSCD
北大核心
2007年第6期1290-1300,共11页
Chinese Journal of Atmospheric Sciences
基金
中国科学院知识创新重要方向性项目KZCX3-SW-226
国家重点基础研究发展规划项目2004CB418303
国家自然科学基金资助项目40523001
关键词
东、西部降水型
外强迫
动力过程
年代际变化
the precipitation pattern in China, extra-forcing factor, internal dynamic processes, interdecadal variation
