重庆羊子洞石笋记录的92.3~60.1 ka亚洲夏季风变化特征  

Variation Characteristics of Asian Summer Monsoon at 92.3-60.1ka Revealed by Stalagmite Records of Yangzi Cave in Chongqing

作　　者：张日萍 杨勋林[1,2,3] 鄢应燃 张瑞 组里塞斯 王勇 ZHANG Riping;YANG Xunlin;YAN Yingran;ZHANG Rui;Zulisaisi;WANG Yong(School of Geographical Sciences/Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station,Southwest University,Chongqing 400715,China;Chongqing Key Laboratory of Karst Environment,Chongqing 400715,China;Field Scientific Observation&Research Base of Karst Eco-Environments at Nanchuan in Chongqing,Ministry of Natural Resources of the People's Republic of China,Chongqing 400715,China)

机构地区：[1]西南大学地理科学学院/重庆金佛山喀斯特生态系统国家野外科学观测研究站,重庆400715 [2]重庆市岩溶环境开放实验室,重庆400715 [3]自然资源部岩溶生态环境—重庆南川野外基地,重庆400715

出　　处：《西南大学学报（自然科学版）》2022年第7期184-196,共13页Journal of Southwest University(Natural Science Edition)

基　　金：国家自然科学基金项目(41971109,41572158);国家重点研发计划项目(2016YFC0502301);中央高校基本科研业务费重大项目(XDJK2012A003)。

摘　　要：深海氧同位素阶段(Marine Isotope Stage, MIS) 5/4转换时期全球气候存在不稳定性,期间发生了一系列百年—千年尺度的气候突变事件.为进一步认识MIS5b-MIS4时期亚洲夏季风演变进程,讨论该时期百年—千年尺度季风突变事件的变化特征,对采自中国西南地区重庆羊子洞的石笋Y01,Y02进行了年龄样品和稳定同位素样品的分析测试,建立了覆盖92.3~60.1 ka(千年前,相对于1950 CE)时段精确定年的高分辨率石笋氧碳同位素记录,重建了MIS5b-MIS4时期的亚洲夏季风演变历史.通过不同记录的对比分析,得出了以下结论:羊子洞石笋δ;O序列记录了5次千年尺度强季风事件中国间冰阶(Chinese Interstadials, CIS)22-18,其发生时间可分别与北格陵兰冰芯项目(North Greenland Ice Core Project, NGRIP)记录中的5次千年尺度暖事件对应.其中Y02δ;O和δ;C序列均完整地记录了强季风事件CIS18,记录表明在CIS18事件期间(64.7~63.2 ka)亚洲夏季风呈现“快速增强,逐渐减弱”的转换特征,并伴随着洞穴外部水热条件的相应变化.在CIS21和CIS20事件结束之前,高分辨率的Y01δ;O序列记录了分别发生于77.4 ka和73.4 ka左右的2次亚千年尺度的季风反弹事件,其与南半球2次温度低谷的对应强调了南半球的逐渐变冷对季风反弹事件发生的促进作用.此外,发现了MIS4早期亚洲夏季风与南极温度的反向关系,表明南半球气候变化对亚洲夏季风的影响.During the Marine Isotope Stage(MIS) 5/4 transition, the global climate was characterized by a series of centennial to millennial-scale abrupt climatic events. In order to further understand the evolution process of Asian summer monsoon(ASM) during MIS5 b-MIS4 and discuss the variation characteristics of the centennial to millennial-scale abrupt monsoonal events that occurred in this period, we analyzed the dating and stable isotope samples of stalagmites Y01 and Y02 collected from Yangzi Cave, Chongqing, Southwest China. We acquired the high-precision;Th-dated stalagmite records covering the interval of 92.3-60.1 ka(thousands of years before 1950 CE), which can be used to construct the ASM evolution history during MIS5 b-MIS4. The δ;O records of Yangzi Cave revealed that the Chinese Interstadials(CIS) 22-18 occurred during the interval of 92.3-60.1 ka, which corresponded to the Greenland Interstadials(GI) 22-18, respectively. In detail, Y02 δ;O and δ;C records showed a complete CIS18 event that occurred between 64.7 and 63.2 ka, during which the ASM experienced a process of rapid strengthening and gradual weakening, accompanied by the changes of environmental conditions above the cave. Before the end of strong monsoonal events CIS21 and CIS20, the high-resolution stalagmite Y01 δ;O recorded two rebound monsoonal events at the sub-millennial scale, which occurred at 77.4 ka and 73.4 ka, respectively. Comparison of those records showed the role of the gradual cooling of the Southern Hemisphere on the promoting of the occurrence of rebound monsoonal events. In addition, there was an inverse relationship between the ASM and the Antarctic temperature at the centennial to millennial scale in the early MIS 4, indicating that the climate change in the Southern Hemisphere had an important effect on the Asian summer monsoon.

关 键 词：石笋氧碳同位素 亚洲夏季风 千年尺度事件 南半球作用 

分 类 号：P532[天文地球—古生物学与地层学] P597.2[天文地球—地质学]