Pacific decadal oscillation impact on East China precipitation and its imprint in new geological documents  

作　　者：Jiahui YAO Linxiang XIAO Mengmeng GOU Chao LI Ergang LIAN Shouye YANG 

机构地区：[1]State Key Laboratory of Marine Geology,Shanghai 200092,China [2]Laboratory for Marine Geology,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266061,China [3]Third Institute of Oceanography,State Oceanic Administration,Xiamen 361005,China

出　　处：《Science China Earth Sciences》2018年第4期473-482,共10页中国科学（地球科学英文版）

基　　金：supported by National Natural Science Foundation of China(Grant No.41676035);the National Programme on Global Change and Air-Sea Interaction(Grant No.GASIGEOGE-03);SITP10

摘　　要：This paper briefly introduces the history of the study of the Pacific decadal oscillation(PDO) and explores the relationship between the PDO and sediment grain size from two typical sediment cores from the lower Changjiang(Yangtze River) and Huanghe(Yellow River) estuaries. It is found that the median grain sizes of both cores exhibit relatively high correlation with the PDO. This is because the PDO causes interdecadal variability of precipitation in the East Asia Monsoon region, thus changing the hydrodynamics in both the Changjiang and Huanghe catchments, eventually resulting in variation of sediment grain size. Our analysis also revealed that during different phases of the PDO, the sediment grain size of the Changjiang and Huanghe estuaries showed different variations in cold and warm PDO phases. This is related to movement of the precipitation center driven by the shift in different PDO phases. Moreover, we compared more high resolution geological proxies with the PDO, including stalagmites and tree rings, in East China over the past century. The results indicate that variations of studied geological proxies are generally well correlated with the PDO but have some differences. Finally, longer variations of sediment grain sizes in the Changjiang and Huanghe estuaries are compared with a reconstructed PDO over the last 200 years;sediment grain sizes were still correlated with the PDO, implying that sediment grain size may be used as a new proxy for studying the long-term behavior of the PDO. This result supports previous knowledge of the PDO impact on East China climate evolution and offers a new proxy for further PDO study. Our study will improve paleoenvironment reconstruction in East China on a decadal time scale and benefit future climatic predictions.This paper briefly introduces the history of the study of the Pacific decadal oscillation（PDO） and explores the relationship between the PDO and sediment grain size from two typical sediment cores from the lower Changjiang（Yangtze River） and Huanghe（Yellow River） estuaries. It is found that the median grain sizes of both cores exhibit relatively high correlation with the PDO. This is because the PDO causes interdecadal variability of precipitation in the East Asia Monsoon region, thus changing the hydrodynamics in both the Changjiang and Huanghe catchments, eventually resulting in variation of sediment grain size. Our analysis also revealed that during different phases of the PDO, the sediment grain size of the Changjiang and Huanghe estuaries showed different variations in cold and warm PDO phases. This is related to movement of the precipitation center driven by the shift in different PDO phases. Moreover, we compared more high resolution geological proxies with the PDO, including stalagmites and tree rings, in East China over the past century. The results indicate that variations of studied geological proxies are generally well correlated with the PDO but have some differences. Finally, longer variations of sediment grain sizes in the Changjiang and Huanghe estuaries are compared with a reconstructed PDO over the last 200 years;sediment grain sizes were still correlated with the PDO, implying that sediment grain size may be used as a new proxy for studying the long-term behavior of the PDO. This result supports previous knowledge of the PDO impact on East China climate evolution and offers a new proxy for further PDO study. Our study will improve paleoenvironment reconstruction in East China on a decadal time scale and benefit future climatic predictions.

关 键 词：Sedimentary record δ^18O in stalagmite Precipitation Pacific decadal oscillation（PDO） East Asian Monsoon 

分 类 号：P461.2[天文地球—大气科学及气象学]