155—20 ka BP中国黄土高原降雨量与温度关系  

Relationship between precipitation and temperature on Chinese Loess Plateau during 155-20 ka BP

作　　者：张紫赟 杨萍果[1] 张鹏[2] 李欣霞 贺凯洋 敖红[2] ZHANG Ziyun;YANG Pingguo;ZHANG Peng;LI Xinxia;HE Kaiyang;AO Hong(School of Life Science,Shanxi Normal University,Taiyuan 030031,China;State Key Laboratory of Loess and Quaternary Geology,Institute of Earth and Environment,CAS,Xi'an 710061,China;School of Earth Sciences,China University of Geosciences(Wuhan),Wuhan 430074,China;State Key Laboratory of Continental Dynamic,Department of Geology,Northwest University,Xi'an 710069,China)

机构地区：[1]山西师范大学生命科学学院,太原030031 [2]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710061 [3]中国地质大学(武汉)地球科学学院,武汉430074 [4]西北大学地质学系大陆动力学国家重点实验室,西安710069

出　　处：《地理学报》2025年第1期120-131,共12页Acta Geographica Sinica

基　　金：国家自然科学基金项目(42261144739,42074076);山西省研究生教育创新计划(2021YJJG143)。

摘　　要：东亚季风影响着数亿人的生活,因此了解其在深海氧同位素第五阶段(MIS 5,130—70ka BP)的演化特征,对于更好地理解亚洲气候变化非常重要。本文以黄土高原中北部环县剖面155—20 ka BP黄土—古土壤序列为研究对象,开展岩石磁学、环境磁学和漫反射光谱研究,以揭示MIS 5期间黄土高原季风降雨与温度变化的关系。岩石磁学结果表明,环县黄土—古土壤序列的磁性矿物以成土细粒磁铁矿/磁赤铁矿为主,多数颗粒粒径从超顺磁(SP)/单畴(SD)到准单畴(PSD),即从<30~1000 nm。环境磁学和漫反射光谱研究表明,黄土高原在MIS 5比MIS 6和MIS 2~4具有更高的降雨量和温度,这表明在轨道(冰期—间冰期)时间尺度上,地质历史时期季风降雨与温度之间存在耦合关系。同时发现在MIS 5期间温度呈降低趋势而降雨量没有降低趋势,表明黄土高原中北部季风降雨与温度在MIS 5期间的变化趋势是非耦合的。The East Asian monsoon plays a crucial role in linking the climate systems of the Northern and Southern Hemispheres,affecting the lives of hundreds of millions of people.There,understanding the evolutionary traits from previous warm periods,such as the deep-sea oxygen isotope stage 5(MIS 5,130-70 ka BP),is crucial to comprehending the pattern of climate change in Asia and the mechanisms causing it.The MIS 5,with its lengthy duration and significant amplitude of climatic changes,is the warmer period closer to us and has been extensively utilized in studies of Late Pleistocene climate change.Here,we report new rock magnetic,environmental magnetic,and diffuse reflectance spectroscopy from the Huanxian loess-paleosol sequence from 155 to 20 ka BP,north-central Loess Plateau to study the relationship between monsoon precipitation and temperature changes during MIS 5.Rock magnetics results indicate that the magnetic minerals of the loess-paleosol sequence in Huanxian are dominated by pedogenic fine-grained magnetite/maghemite,with grain sizes ranging from superparamagnetic(SP)/single-domain(SD)to small pseudo-single domain(PSD)sizes(i.e.,from<30 nm to~1000 nm).The environmental magnetic and diffuse reflectance spectroscopy results indicated that the Loess Plateau had higher precipitation and temperature during MIS 5 than MIS 2-4,and MIS 6,suggesting a coupled relationship between them in the geologic period on the orbital(glacial-interglacial)time scale.During MIS 5,it is discovered that there was a decreasing trend in temperature but not in precipitation,indicating that the trend of precipitation and temperature in the north-central of Chinese Loess Plateau were decoupled.Our research demonstrates that temperature and precipitation in the study area have always had a coupling and decoupling relationship.Combining a detailed land-sea comparison,we suggest that both monsoon precipitation and temperature changes are influenced by ice volume and atmospheric CO2 concentration in the Northern Hemisphere.Additionally,monsoon

关 键 词：环境磁学 MIS 5 古气候 中国黄土高原 黄土—古土壤序列 

分 类 号：P426.6[天文地球—大气科学及气象学] P423