马乐^1,,
肖海燕¹,
张鑫¹,
姜修洋^1,2,,,
蔡炳贵^1,2
1. 福建师范大学地理科学学院, 湿润亚热带生态地理过程教育部重点实验室, 福建 福州 350007
2. 福建师范大学地理研究所, 福建 福州 350007

基金项目: 国家自然科学基金项目（批准号：41672170）、福建省自然科学基金项目（批准号：2017J01654）和福建省高校新世纪优秀人才支持计划共同资助


详细信息

作者简介: 马乐, 男, 25岁, 硕士研究生, 自然地理专业, E-mail:lemxz001@163.com

通讯作者: 姜修洋, E-mail:xyjiang@fjnu.edu.cn

中图分类号: P597⁺.2;P532

收稿日期:2020-01-02
修回日期:2020-04-26
刊出日期:2020-07-30

AN EXCEPTIONALLY STRENGTHENED EAST ASIAN SUMMER MONSOON EVENT BETWEEN 19.0 KA B.P.AND 17.6 KA B.P.RECORDED IN A STALAGMITE FROM XIANYUN CAVE,FUJIAN PROVINCE,SOUTHEASTERN CHINA

Ma Le^1,,
Xiao Haiyan¹,
Zhang Xin¹,
Jiang Xiuyang^1,2,,,
Cai Binggui^1,2
1. Key Laboratory of Humid Subtropical Eco-geographical Processes, Ministry of Education, College of Geography Science, Fujian Normal University, Fuzhou 350007, Fujian
2. Institute of Geography, Fujian Normal University, Fuzhou 350007, Fujian


More Information

Corresponding author: Jiang Xiuyang,E-mail:xyjiang@fjnu.edu.cn

MSC: P597⁺.2;P532

--> Received Date: 02 January 2020
Revised Date: 26 April 2020
Publish Date: 30 July 2020


摘要
摘要:末次冰盛期回暖事件（19.0~17.6 ka B.P.）对于理解末次冰期终止机制具有重要意义。本文根据福建仙云洞石笋（XY7）的16个高精度²³⁰Th年龄和327组δ¹⁸O数据，重建了26.4~14.9 ka B.P.期间十年际分辨率的东亚夏季风演变过程，清晰地捕捉到了发生在末次冰盛期的夏季风增强事件。仙云洞记录指示这一强季风事件发生在19.0~17.6 ka B.P.。尽管亚洲季风区各地洞穴石笋都明确记录了这一强夏季风事件，但仙云洞记录的振幅要小很多，仅为0.5 ‰。这可能与仙云洞位于受东亚夏季风影响的前缘地带，受低纬海洋水文循环过程影响强烈，降水同位素的季节性差异相对较小有关。通过与高低纬地区古气候记录的分析对比表明，末次冰盛期晚期受到太阳辐射升高、北大西洋径向翻转环流增强和热带太平洋Super-ENSO的共同影响，东亚夏季风在19.0~17.6 ka B.P.期间显著增强。
关键词: 仙云洞/
石笋/
末次冰盛期/
夏季风增强

Abstract:The warming episode (19.0~17.6 ka B.P.) during the Last Glacial Maximum (LGM) is a key to understand the mechanism of the termination of the last glacial period. This warming event has been reported in numerous records across the world, which often caused enhancement of a millennial-scale strengthed monsoon event.
Here, we present a high-resolution stalagmite isotope (δ¹⁸O) record from Xianyun Cave (25°33'N, 116°59'E; 970 m a. s. l.) in Fujian Province. The monthly mean temperature inside the cave is ca.17.5℃, relative humidity inside the cave maintains 100% throughout the year. The stalagmite (number:XY7) sample collected in the right branch gallery of Xianyun Cave is 330 mm long and 70~75 mm wide. Based on 16 ²³⁰Th ages and 327 stalagmite δ¹⁸O data, we reconstructed the changes of East Asian Summer Monsoon (EASM) from 26.4 ka B.P. to 14.9 ka B.P. (before 1950 A.D.), yielding an average resolution of 35 a. The three stalagmite δ¹⁸O records of Xianyun cave show remarkable similarities during their overlapping growth interval. The replication of these records confirms that the stalagmites were very likely deposited under isotopic equilibrium conditions and the δ¹⁸O signal recorded in these stalagmites is primarily dominated by climate change.
The Xianyun Cave δ¹⁸O record captures this millennial-scale strong monsoon events that occurred in 19.0~17.6 ka B.P., which was also seen in other stalagmite records from Asian monsoon region. Compared with other monsoon sensitive records, the amplitude of Xianyun Cave δ¹⁸O record is much smaller, i.e., only 0.5 ‰. During this reconstruction period, the changes of δ¹⁸O are 1.7 ‰, 1.5 ‰ and 1.8 ‰ in Xianglong Cave, Hulu Cave and Bittoo Cave, respectively. Low amplitude of δ¹⁸O at our site may be attributed to the fact that our study site has a small amplitude of the seasonal precipitation δ¹⁸O, as it is located in the front area of the EASM and influenced by the low-latitude ocean hydrological cycle process. Co-varying patterns between our records and other high-and low-latitudes Paleoclimatic records suggest that the changes of boundary conditions in the late Last Glacial Maximum, such as the rising solar radiation, the enhancement of meridional circulation in the North Atlantic, and the tropical pacific super-ENSO conditions have contributed significantly to the strengthening of the EASM.
Key words:Xianyun Cave/
stalagmite/
Last Glacial Maximum/
East Asian summer monsoon event



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