On the timing of the East Asian summer monsoon maximum during the Holocene Does the speleothem oxygen isotope record reflect monsoon rainfall variability?  

作　　者：CHEN JianHui RAO ZhiGuo LIU JianBao HUANG Wei FENG Song DONG GuangHui HU Yu XU QingHai CHEN FaHu 

机构地区：[1]Key Laboratory of West China's Environmental System(Ministry of Education),College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,China [2]Department of Geosciences,University of Arkansas,Fayetteville,AR 72701,USA [3]Institute of Nihewan Archaeology Research,Hebei Normal University,Shijiazhuang 050024,China

出　　处：《Science China(Information Sciences)》2016年第12期2328-2338,共11页中国科学（信息科学）（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.41130102&41471162);the Fundamental Research Funds for the Central Universities(Grant Nos.LZUJBKY-2015-K09&LZUJBKY-2015-124);JC is partially supported by the Chinese Scholarship Council

摘　　要：The evolution of the East Asian summer monsoon （EASM） during the Holocene has long been of significant interest. Knowledge of past EASM variability not only increases our understanding of monsoon dynamics on a long timescale, but it also provides an environmental and climatic background for research into Chinese cultural development. However, the timing of the EASM maximum remains controversial. The popular concept of an ＂early Holocene maximum＂ is mainly based on speleothem δ18O （δ18Oc） records from caves in southern China; however, the interpretation of δ18Oc as a reliable proxy for EASM intensity is being increasingly challenged. The present paper is a critical review of the climatic significance of the δ18Oc record from China. Firstly, we suggest that precipitation in northern China is an appropriate index of EASM intensity, the variation of which clearly indicates a mid-Holocene monsoon maximum. Secondly, an interregional comparison demonstrates that the precipitation record in northern China is quite different from that in southern China on a range of timescales, and is inconsistent with the spatial similarity exhibited by speleothem oxygen isotope records. Furthermore, both modeling and observational data show that the δ18Oc records from southern China indeed reflect changes in precipitation δ18O （δ18Op） rather than precipitation amount, and therefore that their use as an EASM proxy is inappropriate. Finally, we address several significant monsoon-related issues--including the driving mechanism of the EASM on an orbital timescale, the climatic significance of speleothem oxygen isotopes, and the relationship between atmospheric circulation and precipitation in monsoonal regions.The evolution of the East Asian summer monsoon （EASM） during the Holocene has long been of significant interest. Knowledge of past EASM variability not only increases our understanding of monsoon dynamics on a long timescale, but it also provides an environmental and climatic background for research into Chinese cultural development. However, the timing of the EASM maximum remains controversial. The popular concept of an ＂early Holocene maximum＂ is mainly based on speleothem δ18O （δ18Oc） records from caves in southern China; however, the interpretation of δ18Oc as a reliable proxy for EASM intensity is being increasingly challenged. The present paper is a critical review of the climatic significance of the δ18Oc record from China. Firstly, we suggest that precipitation in northern China is an appropriate index of EASM intensity, the variation of which clearly indicates a mid-Holocene monsoon maximum. Secondly, an interregional comparison demonstrates that the precipitation record in northern China is quite different from that in southern China on a range of timescales, and is inconsistent with the spatial similarity exhibited by speleothem oxygen isotope records. Furthermore, both modeling and observational data show that the δ18Oc records from southern China indeed reflect changes in precipitation δ18O （δ18Op） rather than precipitation amount, and therefore that their use as an EASM proxy is inappropriate. Finally, we address several significant monsoon-related issues--including the driving mechanism of the EASM on an orbital timescale, the climatic significance of speleothem oxygen isotopes, and the relationship between atmospheric circulation and precipitation in monsoonal regions.

关 键 词：East Asian summer monsoon HOLOCENE Speleothem oxygen isotopes 

分 类 号：TP[自动化与计算机技术]