The influence of proxy selection on global annual mean temperature reconstructions during the Common Era  

作　　者：Bao YANG Xia LI Minhui HE Feng WANG Yesi ZHAO Peng ZHANG Jianglin WANG 

机构地区：[1]Frontiers Science Center for Critical Earth Material Cycling,School of Geography and Ocean Science,Nanjing University,Nanjing 210023,China [2]Key Laboratory of Desert and Desertification,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China [3]Centre Eau Terre Environnement,Institut National de la Recherche Scientifique,Québec,QC,G1K 9A9,Canada [4]GEOTOP Research Centre in the Dynamics of the Earth System,Montréal,QC H2X 3Y7,Canada

出　　处：《Science China Earth Sciences》2024年第8期2522-2534,共13页中国科学（地球科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.42130511,42488201);the“Geo X”Interdisciplinary Research Funds for the Frontiers Science Center for Critical Earth Material Cycling,Nanjing University(Grant Nos.202330029&2023300286)。

摘　　要：The reconstruction of global annual mean temperatures made by the PAGES 2k Consortium in 2019 represents one of the most influential sequences of global climate variability over the Common Era.However,it is still not clear how the reconstruction can be influenced by the selection of reconstruction methods and the selection of proxy records with different temporal resolutions over different regions.We adopt a widely used Composite-Plus-Scale method to elucidate the effects of the selection of the proxy records on temperature reconstruction.To ensure the uniformity of data,different types of proxy records spanning the past~2000 years from the PAGES 2k proxy network were used to investigate the potential effects of proxy selection in hemispheric and global temperature reconstructions during the past two millennia.The long-term trends,spectral characteristics,and volcanic responses of the annual temperatures were studied based on the reconstructions.Our results reveal a significant cooling trend in the global annual mean temperature using both tree-ring and non-tree-ring records during the 1–1850CE period,and show that the cooling exhibits a stronger trend in the Southern Hemisphere(SH)than that in the Northern Hemisphere(NH).Yet,the long-term trends vary according to different combinations of proxy records.Different reconstructions based on different types of proxies also exhibit different features in terms of volcanic responses and spectral properties.Tree-ring-based temperature reconstructions show stronger cooling responses to tropical volcanic eruptions,while non-tree-ring-based reconstructions suggest less robust volcanic responses,which may be related to dating uncertainties and low temporal resolution of the proxies.Tree-ring width records tend to preserve a substantial proportion of high-frequency(<200 years)variability,whereas non-tree-ring proxies tend to capture a larger fraction of low-frequency(>200 years)variations.Efforts are needed to reduce uncertainties of the temperature reconstruction over the

关 键 词：Millennial cooling trend Global climate change Proxy records Volcanic eruptions Spectral properties Common Era 

分 类 号：P532[天文地球—古生物学与地层学]