大气科学  2018, Vol. 42 Issue (3): 533-558   PDF    
论东亚夏季风的特征、驱动力与年代际变化
丁一汇1, 司东1, 柳艳菊1, 王遵娅1, 李怡2, 赵亮3, 宋亚芳1     
1 中国气象局国家气候中心, 北京 100081
2 中国气象局公共气象服务中心, 北京 100081
3 中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室(LASG), 北京 100029
摘要: 本文是以新的资料和研究结果对东亚夏季风的基本特征、驱动力和年代际变化所作的重新分析与评估。内容包括四个部分:(1)东亚夏季风的基本特征;(2)东亚夏季风的驱动力;(3)东亚夏季风的年代际变率与原因;(4)东亚夏季风与全球季风的关系。结果表明:东亚夏季风是亚洲夏季风的一个重要有机部分,主要由来源于热带的季风气流组成,并随季节由南向北呈阶段性推进,它是形成夏季东亚天气与气候的主要环流和降水系统。驱动夏季风的主要强迫有三部分:外部强迫、耦合强迫与内部变率,其中人类活动引起的外强迫(气候变暖、城市化、气溶胶增加等)是新出现的外强迫,它正不断改变着东亚夏季风的特征与演变趋势。海洋与陆面耦合强迫作为自然因子是引起东亚夏季风年际和年代际变化的主要原因,其中太平洋年代尺度振荡(PDO)与北大西洋多年代尺度振荡(AMO)的协同作用是造成东亚夏季风30~40年周期振荡的主要原因。1960年代以后,东亚夏季风经历了强—弱—强的年代际变化,相应的中国东部夏季降水型出现了“北多南少”向“南涝北旱”以及“北方渐增”的转变。最近的研究表明,上述东亚夏季风年代际变化与整个亚非夏季风系统的变化趋势是一致的。在本世纪主要受气候变暖的影响,夏季风雨带将持续北移,中国北方和西部地区出现持续性多雨的格局。最后本文指出,亚非夏季风系统相比于其他区域季风系统更适合全球季风的概念。
关键词: 东亚夏季风      夏季风特征      季风驱动力      年代际变化      全球季风     
On the Characteristics, Driving Forces and Inter-decadal Variability of the East Asian Summer Monsoon
DING Yihui1, SI Dong1, LIU Yanju1, WANG Zunya1, LI Yi2, ZHAO Liang3, SONG Yafang1     
1 National Climate Center, China Meteorological Administration, Beijing 100081
2 Public Meteorological Service Center, China Meteorological Administration, Beijing 100081
3 State Key Laboratory of Numerical Modeling for Atmosphere Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029
Abstract: The present paper has reanalyzed and reassessed the basic characteristics, the driving forces and the inter-decadal variability of the East Asian summer monsoon with new-inputs of data and research findings. It includes four parts:(1) the basic characteristic features and properties of the East Asian summer monsoon; (2) the driving forces of the East Asian summer monsoon; (3) the inter-decadal variability of the East Asian summer monsoon, and (4) the association of the East Asian monsoon with the global monsoon. The results obtained here have shown that the East Asian summer monsoon is an important and integrated part of the Asian summer monsoon system, with the monsoonal airflow of tropical origin. It is the main circulation and precipitation system in summer to shape the weather and climate in East Asia. The main forces that drive the East Asian summer monsoon consist of three kinds:external forcing, coupled forcing and internal variability. Among them, the anthropogenic external forcing (e.g., greenhouse gas, urbanization effect, and aerosols), which is an emerging driving force, is changing the properties and evolution trend of the East Asian summer monsoon. As a nature factor, the coupled forcing of oceanic and land-surface processes is the main cause of the inter-decadal variability of the East Asian summer monsoon. The coordinated effect of the Pacific Decadal Oscillation (PDO) and the Atlantic Multi-decadal Oscillation (AMO) is the dominant forcing for the 30-40 year period. Since the 1960s, the East Asian summer monsoon has experienced a strong-weak-strong inter-decadal scale evolution, along with the PDO and AMO. Correspondingly, the precipitation pattern in East China has also shifted from the "North flooding and South drought" pattern to the "North drought and South flooding" pattern with increasing precipitation in North China in the recent decade. Actually, this inter-decadal variation is consistent with the change of the Afro-Asian summer monsoon system. In the present century, influenced by increasing climate warming, the summer monsoon precipitation belt will continue to advance northward, and therefore northern and western China will have persistent above-normal precipitation scenarios. Finally, it is indicated that the Afro-Asian summer monsoon is well corresponding to the concept of the global monsoon compared to other regional monsoons worldwide.
Key words: East Asian summer monsoon      Characteristics of the East Asian summer monsoon      Monsoon driving force      Inter-decadal variability      Global monsoon     
1 引言

关于东亚季风系统的气候特征、性质、季节进退与变率及其对东亚(中国、日本、朝鲜半岛等地区)大尺度环流和天气—气候的影响已有许多研究和总结(Ramage, 1971; Murakam, 1986; Tao and Chen, 1987;