Hydroclimate changes related to thermal state of the tropical Pacific in the northern coast of the South China Sea since~8000 cal yr B.P.  

作　　者：Yue-Qin Wu Xiao-Qiang Yang Jian Yin Franz TFürsich Ting-Wei Zhang Chun-Lian Liu 

机构地区：[1]Guangdong Provincial Key Laboratory of Geodynamics and Geohazards,School of Earth Sciences and Engineering,Sun Yat-Sen University,Zhuhai 519082,Guangdong Province,China [2]Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519082,Guangdong Province,China [3]FG Paläoumwelt,GeoZentrum Nordbayern der Friedrich-Alexander-Universität Erlangen-Nürnberg,Erlangen 91054,Germany

出　　处：《Journal of Palaeogeography》2022年第3期410-426,共17页古地理学报（英文版）

基　　金：supported by Guangdong Province Introduced Innovative R&D Team of Geological Processes and Natural Disasters around the South China Sea(Grant no.2106ZT06N331);the National Natural Science Foundation of China(Grant no.41872217);Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant no.311021004)。

摘　　要：Under the complex influences including the monsoonal climates and tropical hydrological cycle,the features and forcing mechanisms of precipitation changes in the tropical monsoon regions remain controversial.The northern coast of the South China Sea(NCSCS),connecting the South China Sea(SCS)and the Pearl River Estuary(PRE),is a critical area providing reliable tropical precipitation records and probing the possible forcing mechanism of tropical precipitation,benefitted from its high deposition rate and hydroclimatic sensitivity.Here,δ^(18)O variations of planktonic(δ^(18)O_(G).ruber)and benthic foraminifera(δ^(18)O_(C).lobatulus)were investigated respectively to reconstruct a high-resolution low-latitude precipitation record from the core 17NH-NC3 in the NCSCS.The results show a distinctδ^(18)O difference betweenδ^(18)O_(G).ruber andδ^(18)O_(C).lobatulus,not only with respect to values,but also with respect to trends in some time intervals.The clear difference between the planktonic and benthic foraminifera(Δδ^(18)O_(b-p))illustrates the significant vertical salinity stratification.And the temporal trend ofΔδ^(18)O_(b-p) indicates the degree of salinity stratification variated since the mid-Holocene.We assume that the degree of stratification in the NCSCS was mainly controlled by tropical precipitation changes.Thus,the trend ofΔδ^(18)O_(b-p) values could indicate the temporal change of the tropical precipitation.The precipitation record of our research area is closely related to the tropical atmosphere–ocean dynamics stimulated by sea surface temperature(SST)changes of the tropical Pacific zone,analogous to the El Niño–Southern Oscillation(ENSO)events.During the mid-Holocene(from 8260 to 5180 cal yr B.P.),the sustainable higherΔδ^(18)O_(b-p) values(>1.23‰)suggested a large amount of precipitation,pointing to a sustained state of La Niña-like,which is associated with lasted higher difference between Western SST and Eastern SST(W-E SST gradient)in the equatorial Pacific.Since 5180 cal yr B.P.,

关 键 词：Stable oxygen isotope Globigerinoides ruber Cibicides lobatulus Low-latitude precipitation ENSO MID-HOLOCENE 

分 类 号：P732[天文地球—海洋科学]