Model-based orbital-scale precipitationδ18O variations and distinct mechanisms in Asian monsoon and arid regions  

作　　者：Xiaodong Liu Xiaoxun Xie Zhengtang Guo Zhi-Yong Yin Guangshan Chen 

机构地区：[1]State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710061,China [2]Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China [3]University of Chinese Academy of Sciences,Beijing 100049,China [4]Department of Environmental&Ocean Sciences,University of San Diego,San Diego,CA 92110,USA

出　　处：《National Science Review》2022年第11期126-143,共18页国家科学评论（英文版）

基　　金：supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB40030100);the National Natural Science Foundation of China (41888101,41991254, 41690115 and 42105049)

摘　　要：The past Asian precipitationδ^(18)O(δ^(18)O_(p))records from stalagmites and other deposits have shown significant orbital-scale variations,but their climatic implications and regional differences are still not fully understood.This study,as the first attempt of a 300-kyr transient stable isotope-enabled simulation,investigated the characteristics and mechanisms of the orbital-scaleδ^(18)O_(p)variations in three representative regions of Asia:arid Central Asia(CA),monsoonal South Asia(SA)and monsoonal East Asia(EA).The modelling results showed that the variations in the CA,SA and EA annualδ^(18)O_(p)exhibited significant but asynchronous 23-kyr precession cycles.Further analyses revealed that although the precession-induced insolation variation was the ultimate cause of theδ^(18)O_(p)variation in all three regions,the dominant mechanisms and the involved physical processes were distinct among them.For the CA region,the rainy-season(November–March)temperature effect and water vapour transport by the westerly circulation were identified as the key precession-scale processes linking the October–February boreal mid-latitude insolation to the rainy-season or annualδ^(18)O_(p).In the SA region,the rainy-season(June–September)precipitation amount effect and upstream depletion of the monsoonal water vapourδ^(18)O served as the main mechanisms linking the rainy-season or annualδ^(18)O_(p)to the April–July insolation variation at the precession scale.For the EA region,however,the precession-scale annualδ^(18)O_(p)was mainly controlled by the late-monsoon(August–September)and pre-monsoon(April–May)water vapour transport patterns,which were driven by the July–August insolation and the global ice volume,respectively.These results suggest that the climatic implications of the orbital-scale Asiaδ^(18)O_(p)variations are sensitive to their geographic locations as determined by the combined effects of insolation and regional circulation patterns associated with the respective rainy seasons.This study provi

关 键 词：orbital scale precipitationδ18O transient simulation Asian monsoon arid region 

分 类 号：P467[天文地球—大气科学及气象学]