哈尔滨黄土粒度端元对比分析及其气候意义  

Comparative analysis of grain size end member of Harbin loess and climatic significance

作　　者：宋莹 迟云平[1,2] 谢远云[1,2] 康春国[3] 魏振宇 吴鹏 孙磊 刘若男 SONG Ying;CHI Yunping;XIE Yuanyun;KANG Chunguo;WEI Zhenyu;WU Peng;SUN Lei;LIU Ruonan(College of Geographic Science,Harbin Normal University,Harbin 150025,China;Heilongjiang Province Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Regions,Harbin Normal University,Harbin 150025,China;Geography Department,Harbin Institute,Harbin 150086,China)

机构地区：[1]哈尔滨师范大学地理科学学院,哈尔滨150025 [2]哈尔滨师范大学寒区地理环境监测与空间信息服务黑龙江省重点实验室,哈尔滨150025 [3]哈尔滨学院地理系,哈尔滨150086

出　　处：《地理科学进展》2023年第9期1825-1840,共16页Progress in Geography

基　　金：国家自然科学基金项目(42171006,41601200);黑龙江省自然科学基金项目(ZD2023D003);哈尔滨师范大学博士启动基金项目(XKB201418)。

摘　　要：哈尔滨黄土作为东亚风尘沉积系统的重要组成部分,对中国东北地区气候变化研究具有重要意义。粒度端元分析被广泛用于黄土沉积物的研究中,能够有效反演粉尘传输机制与古气候变化。已有的研究中,对哈尔滨地区不同粒级组分所指示的搬运动力及环境意义研究较少。论文在综合对比Analysize、BasEMMA与BEMMA三种端元分析方法的基础上,结合粒级—标准偏差法,评估不同粒度端元分析方法在哈尔滨黄土—古土壤中的适用性,明确其环境意义。结果表明:Analysize方法在哈尔滨黄土—古土壤粒度端元提取中具有较好的适用性,而BasEMMA与BEMMA方法效果相对较差。哈尔滨黄土提取出3个有效粒级组分,即EM1(7.81μm)为大气背景粉尘;EM2(27.2μm)为较远源粉尘的贡献,代表夏季风信号;EM3(54.41μm)为近源输入,指示冬季风强度。综合深海氧同位素、北太平洋风尘质量累计率、与65°N太阳辐射量,发现哈尔滨地区250 ka之前,冬季风占主导,且表现出明显的冰期—间冰期旋回特征,高纬强迫下冰量驱动是导致该时期气候变化的主要因素;250 ka之后,该区气候呈现逐渐变暖湿的宏观趋势,且黄土粒度端元没有表现出明显的冰期—间冰期旋回特征,北半球高纬夏季接受太阳辐射增强,使东亚冬季风减弱,西北方向物源区粉尘贡献减少以及松嫩沙地范围收缩,是导致这一现象的主要原因。As an important part of the East Asian aeolian sediment system,Harbin loess is of great significance for the study of climate change in Northeast China.Grain size end-member analysis is widely used in the study of loess sediments,which can effectively retrieve the mechanism of dust transport and paleoclimate change.In the existing studies,few have examined the transport power and environmental significance indicated by different size fractions in the loess deposit of Harbin.Based on a comprehensive comparison of Analysize,BasEMMA,and BEMMA end-member analysis methods,and combined with the particle size-standard deviation method,this study evaluated the applicability of different particle size end-member analysis methods in Harbin loess-paleosol,and clarified its environmental significance.The results show that the Analysize method has a good applicability in the end-member extraction of grain size of loess-paleosol in Harbin,while the performance of BasEMMA and BEMMA methods are relatively poor.Three effective grain size components were extracted from Harbin loess:EM1(7.81μm),which is the atmospheric background dust;EM2(27.2μm),which is the contribution of distant dust,representing the summer monsoon signal;and EM3(54.41μm),which is the near source input,indicating the winter monsoon intensity.Based on the analysis of marine isotope stages,mass accumulation rate(MAR),and 65°N solar radiation,this study found that before 250 ka in Harbin,the winter wind was dominant and showed obvious glacial-interglacial cycle characteristics.The driving force of ice volume in high latitudes was the main factor leading to climate change in this period;After 250 ka,the climate in this area showed an overall trend of gradual warming and increasing humidity,and the loess grain size end members did not show obvious glacial-interglacial cycle characteristics.The main cause of this phenomenon was the increased solar radiation in the high latitudes of the northern hemisphere in the summer,which weakened the East Asian winter monsoon

关 键 词：哈尔滨黄土 粒度 端元分析 粒级标准偏差 气候演化 

分 类 号：P467[天文地球—大气科学及气象学]