Atmospheric insight to climatic signals of δ^18O in a Laohugou ice core in the northeastern Tibetan Plateau during 1960–2006

作     者：WenTao Du ShiChang Kang Xiang Qin XiaoQing Cui WeiJun Sun 

作者机构：Qilian Shan Station of Glaciology and Ecologic Environment State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou Gansu 730000 China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China College of Population Resources and Environment Shandong Normal University Jinan Shandong 250014 China 

出 版 物：《Research in Cold and Arid Regions》 (寒旱区科学（英文版）)

年 卷 期：2016年第8卷第5期

页      面：367-377页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：supported by the Global Change Research Program of China (No. 2013CBA01801) the Natural Science Foundation of China (Nos. 41225002, 41371091, and 41121001) 

主　　题：δ^18O variations ice core outgoing longwave radiation meridional wind northeastern Tibetan Plateau 

摘      要：Ice documentation and response to prominent warming, especially after the 1990s, is further investigated because it is concerned whether ice records have absence. A δ^18O series of a Laohugou （LHG） shallow ice core （20.12 m） in the northeastern Tibetan Plateau was reconstructed covering the period of 1960–2006. The ice core δ^18O record had sig-nificant positive correlations with the warm season （May–September） air temperatures at adjacent meteorological stations and the 500 hPa temperatures in boreal China, indicating that the δ^18O record could be considered a credible proxy of regional temperature. A clear, cold temperature event in 1967 and rapid warming after the 1990s were captured in the LHG δ^18O series, revealing that it could record extreme air-temperature events on both regional and global scales. The LHG δ^18O variations had evident positive correlations with both the summer surface outgoing longwave radiation （OLR） in the Mongolia region and the summer meridional wind at 500 hPa in the LHG region during 1960–2006, suggesting that the increased OLR in the Mongolia region might have intensified the Mongolia Low and expanded the pressure gradient to the LHG region （the Shulehe High）, which would have pushed the westerlies further north and suppressed southward incursions of cold air into the LHG region, and thus augmented the temperature rise. The regional atmospheric circulation difference （1985–2006 minus 1960–1984） suggested that the anticyclone in the Mongolia region might have developed the easterly wind, which transported warmer air from the east toward the LHG region and weakened the cold penetration of the westerlies, resulting in the temperature rise since the middle 1980s.