Millennial-scale East Asian summer monsoon hydroclimate variability during 47–39 kyr B.P. inferred from a stalagmite IRMsoft-flux record in Southeastern China
Yue Li , Wanyin Qiu , Kui Gao , Wenyu Dong , Xiuyang Jiang , Hai Cheng , Chuan-Chou Shen , Yu-Min Chou
{"title":"Millennial-scale East Asian summer monsoon hydroclimate variability during 47–39 kyr B.P. inferred from a stalagmite IRMsoft-flux record in Southeastern China","authors":"Yue Li , Wanyin Qiu , Kui Gao , Wenyu Dong , Xiuyang Jiang , Hai Cheng , Chuan-Chou Shen , Yu-Min Chou","doi":"10.1016/j.gloplacha.2025.104954","DOIUrl":null,"url":null,"abstract":"<div><div>The East Asian Summer Monsoon (EASM) exhibited millennial-scale oscillations during the Last Glacial Period, characterized by alternating cold stadials and warm interstadials that were broadly synchronous with climate changes in the North Atlantic. However, the mechanism linking regional hydroclimate variability to high- and low-latitude forcing remains debated. Here, we present precisely dated speleothem multi-proxy records, including δ<sup>18</sup>O, δ<sup>13</sup>C, and an environmental magnetic proxy (IRM<sub>soft-flux</sub>), spanning 46.92–39.18 kyr B.P. from Xianyun Cave, southeastern China. The IRM<sub>soft-flux</sub>, serves as an indicator of precipitation intensity, revealing increases during Dansgaard-Oeschger (DO) events 12 and 11, consistent with enhanced water vapor influx into southern China. Maximum moisture availability occurred between 43.96 and 42.98 kyr B.P., encompassing the DO 11 event and a weak monsoon interval, as corroborated by concurrent δ<sup>13</sup>C depletion, enhanced growth rate, and high initial <sup>234</sup>U/<sup>238</sup>U ratio. This period of increased hydrological activity coincides with the peak of the half-precession cycle, which influences the vertical temperature gradient in the equatorial western Pacific, as well as the minima of west-east sea surface temperature gradient (ΔSST) in the equatorial Pacific. During this El Niño-like state, a weakened East Asia Hadley circulation (EAHC) and a southward shift of the Western Pacific Subtropical High (WPSH) amplified moisture convergence over southern China. Our findings demonstrate that the thermocline variability in the tropical Pacific, propagated hydroclimatic signals to subtropical East Asia via ocean-atmosphere circulation coupling, particularly affecting regions near the water vapor source from tropical Pacific.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"253 ","pages":"Article 104954"},"PeriodicalIF":4.0000,"publicationDate":"2025-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Global and Planetary Change","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0921818125002632","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOGRAPHY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The East Asian Summer Monsoon (EASM) exhibited millennial-scale oscillations during the Last Glacial Period, characterized by alternating cold stadials and warm interstadials that were broadly synchronous with climate changes in the North Atlantic. However, the mechanism linking regional hydroclimate variability to high- and low-latitude forcing remains debated. Here, we present precisely dated speleothem multi-proxy records, including δ18O, δ13C, and an environmental magnetic proxy (IRMsoft-flux), spanning 46.92–39.18 kyr B.P. from Xianyun Cave, southeastern China. The IRMsoft-flux, serves as an indicator of precipitation intensity, revealing increases during Dansgaard-Oeschger (DO) events 12 and 11, consistent with enhanced water vapor influx into southern China. Maximum moisture availability occurred between 43.96 and 42.98 kyr B.P., encompassing the DO 11 event and a weak monsoon interval, as corroborated by concurrent δ13C depletion, enhanced growth rate, and high initial 234U/238U ratio. This period of increased hydrological activity coincides with the peak of the half-precession cycle, which influences the vertical temperature gradient in the equatorial western Pacific, as well as the minima of west-east sea surface temperature gradient (ΔSST) in the equatorial Pacific. During this El Niño-like state, a weakened East Asia Hadley circulation (EAHC) and a southward shift of the Western Pacific Subtropical High (WPSH) amplified moisture convergence over southern China. Our findings demonstrate that the thermocline variability in the tropical Pacific, propagated hydroclimatic signals to subtropical East Asia via ocean-atmosphere circulation coupling, particularly affecting regions near the water vapor source from tropical Pacific.
期刊介绍:
The objective of the journal Global and Planetary Change is to provide a multi-disciplinary overview of the processes taking place in the Earth System and involved in planetary change over time. The journal focuses on records of the past and current state of the earth system, and future scenarios , and their link to global environmental change. Regional or process-oriented studies are welcome if they discuss global implications. Topics include, but are not limited to, changes in the dynamics and composition of the atmosphere, oceans and cryosphere, as well as climate change, sea level variation, observations/modelling of Earth processes from deep to (near-)surface and their coupling, global ecology, biogeography and the resilience/thresholds in ecosystems.
Key criteria for the consideration of manuscripts are (a) the relevance for the global scientific community and/or (b) the wider implications for global scale problems, preferably combined with (c) having a significance beyond a single discipline. A clear focus on key processes associated with planetary scale change is strongly encouraged.
Manuscripts can be submitted as either research contributions or as a review article. Every effort should be made towards the presentation of research outcomes in an understandable way for a broad readership.