周学琴^1,2,3,,
陈仕涛^1,2,3,,,
王真军^1,2,3,
杨少华^1,2,3,
汪永进^1,2,3,
邵庆丰^1,2,3
1. 南京师范大学地理科学学院, 江苏 南京 210023
2. 虚拟地理环境教育部重点实验室(南京师范大学), 江苏 南京 210023
3. 江苏省地理信息资源开发与利用协同创新中心, 江苏 南京 210023

基金项目: 国家自然科学基金项目（批准号：41572340、41571102和41931178）和江苏省高校优势学科建设工程项目（批准号：164320H116）共同资助


详细信息

作者简介: 周学琴, 女, 23岁, 硕士研究生, 自然地理专业, E-mail:zhouxueqin26@163.com

通讯作者: 陈仕涛, E-mail:chenshitao@njnu.edu.cn

中图分类号: P597⁺.2;P532

收稿日期:2020-02-27
修回日期:2020-05-10
刊出日期:2020-07-30

Response of Asian monsoon events to north-south high latitude climate in the Last Glacial period

Zhou Xueqin^1,2,3,,
Chen Shitao^1,2,3,,,
Wang Zhenjun^1,2,3,
Yang Shaohua^1,2,3,
Wang Yongjin^1,2,3,
Shao Qingfeng^1,2,3
1. School of Geography, Nanjing Normal University, Nanjing 210023, Jiangsu
2. Key Laboratory of Virtual Geographic Environment(Nanjing Normal University), Ministry of Education, Nanjing 210023, Jiangsu
3. Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, Jiangsu


More Information

Corresponding author: Chen Shitao,E-mail:chenshitao@njnu.edu.cn

MSC: P597⁺.2;P532

--> Received Date: 27 February 2020
Revised Date: 10 May 2020
Publish Date: 30 July 2020


摘要
摘要:末次冰期千年尺度亚洲季风事件与南北高纬度气候变化的关联一直是第四纪古气候领域中的热点问题。本文基于湖北省落水洞长830 mm的LS23石笋15个²³⁰Th年龄和830个δ¹⁸O数据，重建了28.7~22.2 ka B.P.和87.0~82.9 ka B.P.两个时段内平均分辨率分别为20 a和15 a的亚洲季风变化序列。石笋LS23记录的24.7~23.4 ka B.P.期间的千年尺度亚洲弱季风事件，对应于H2事件（Heinrich 2 Event）和南极暖事件2（Antarctic Isotope Maximum 2，简称AIM2事件）。该弱季风事件在24.7~23.4 ka B.P.期间呈缓慢开始、缓慢结束的"V"型结构演化模式，与南极对应暖事件的转型特征基本一致，而与北高纬H2事件呈快速开始、快速结束的"U"型结构明显不同，表明此时亚洲季风主要受到南高纬气候变化的影响。在84.9~84.8 ka B.P.期间，亚洲季风快速增强，对应于格陵兰冰芯记录的DO21事件（Dansgaard-Oeschger 21 Event）的开始阶段。特别重要的是，在石笋δ¹⁸O序列中识别出和格陵兰冰芯记录一致的PE事件（Precursor-type Peak Event），这是在南极温度变化中难以发现的，说明此时亚洲季风变化可能主要由北高纬触发。由此推断，末次冰期千年尺度亚洲季风事件与南、北高纬气候的联系受气候背景的影响，冰期（比如H2事件所处的MIS2阶段（Marine Isotope Stage 2，深海同位素2阶段））季风强度变化主要受到南高纬温度的控制，而间冰期（比如DO21事件所处的MIS5a阶段）主要受到北高纬的触发。
关键词: 亚洲季风/
H2事件/
DO21事件/
高纬气候变化/
不同气候背景

Abstract:The teleconnection between Asian monsoon and climate change of the northern and southern high latitudes during the last glacial has been widely recorded in the geological archives. However, how the processes of high latitudes affects millennial-scale events of Asian monsoon is an open question. This paper is based on an 830-mm stalagmite from Luoshui Cave, Central China, to establish high resolution climate series of the Asian monsoon. The goal of this paper is to study the teleconnection between Asian monsoon and process of high latitudes during the glacial cycle.
LS23 was collected in Luoshui Cave (29°44'N, 109°7'E) in Hubei Province, Central China. The altitude of Luoshui Cave is about 975 m. The cave is located in the typical subtropical monsoon region with four distinct seasons. Mean annual temperature around the Luoshui Cave is about 14℃ and the annual precipitation is about 1400 mm. The precipitation from May to September accounts for 67% of the total amount, and a period of rainy season is prevailed by the Asian Summer Monsoon.
The length of stalagmite LS23 is about 830 mm and hiatus are visually inspected at the depth of 308~310 mm and 610~614 mm on the polished surface. 15 sub-samples were collected with a 0.9-mm-diameter carbide dental burs for ²³⁰Th dating. The dates were obtained using a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) at Nanjing Normal University and Nanyang Technological University with error of ±2σ. The chemical procedures were similar to those described in Shao et al. (2017), Li et al. (2019) and Cheng et al. (2013). For stable isotopic measurements, 830 sub-samples were drilled with 1-mm-diameter carbide dental burs per 1 mm of the growth axis. The analysis was conducted on a Finnigan MAT-253 mass spectrometer fitted with a Kied Carbonate Device. Stable isotope measurements were reported to Vienna PeeDee Belemnite (VPDB) and with standardization determined relative to NBS19. Precision of δ¹⁸O was better than 0.06 ‰, VPDB, at the 1-sigma level. LS23 grows at the periods from 28.7 ka B.P. to 22.2 ka B.P. (0~306 mm) and from 87.0 ka B.P. to 82.9 ka B.P. (316~610 mm) as well as from 93.7 ka B.P. to 91.6 ka B.P. (625~830 mm). Here, we focus on the depth of 0~306 mm and 316~610 mm of stalagmite LS23 in this study.
Based on the linear interpolation chronology and calcite δ¹⁸O data of LS23, a detailed evolution history of Asian Monsoon from 28.7 ka B.P. to 22.2 ka B.P. and from 87.0 ka B.P. to 82.9 ka B.P. is reconstructed, and the average resolution of growth periods is about 20 a and 15 a, respectively. 15 U-Th ages accurately define the occurrence period of H2 (Heinrich 2 Event) and DO21 (Dansgaard-Oeschger 21 Event) events. Stalagmite LS23 records the weak monsoon event from 24.7 ka B.P. to 23.4 ka B.P., corresponding to the H2 event (Heinrich 2) in northern hemisphere and the warm event (Antarctic Isotope Maximum 2, AIM2 event) in southern hemisphere. The weak monsoon event recorded by stalagmite LS23 shows a slowly starting and ending pattern with "V"-shaped structure, which is consistent with the evolution pattern of the warm event in Antarctica. The corresponding event recorded by GISP2 shows abruptly starting and ending evolution with "U"-shaped structure, which indicating that Asian monsoon is mainly driven by the climate change of the high latitude in Southern hemisphere. The weakening of Asian monsoon may be related to the decrease of cross-equatorial flow caused by Antarctic warming and the southward migration of ITCZ (Intertropical Convergence Zone). Asian monsoon increased rapidly during the interval from 84.9 ka B.P. to 84.8 ka B.P., corresponding to the beginning of the DO21 event recorded by the GISP2. The rapid evolution of the monsoon recorded by stalagmite LS23 is consistent with the climate change of Northern high latitude. Furthermore, a Precursor-type peak event (PE event) before DO21 event is similar between LS23 and Greenland ice core records, which indicating that Asian monsoon is mainly affected by the process of northern high latitudes during this period. The teleconnection between North Atlantic and hydrologic cycles in low latitude may be the active AMOC (Atlantic Meridional Overturning Circulation) and northward shift of ITCZ. Other geological archives also show that the millennial-scale events are similar to the climate process of Southern and Northern high latitudes during the last glacial and interglacial periods respectively. It is concluded that the millennial changes of monsoon intensity in Asia were mainly affected by the Southern high latitude during the last glacial while driven by the northern high latitude during the last interglacial.
Key words:Asian monsoon/
H2 event/
DO21 event/
high latitude climate change/
different climatic background



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