Moisture variations over the past millennium characterized by Qaidam Basin tree-ring δ^(18)O  

作　　者：WANG WenZhi LIU XiaoHong XU GuoBao SHAO XueMei QIN DaHe SUN WeiZhen AN WenLing ZENG XiaoMin 

机构地区：[1]State Key Laboratory of Cryospheric Sciences,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences [3]Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences

出　　处：《Chinese Science Bulletin》2013年第32期3956-3961,共6页

基　　金：supported by the Global Change Research Program of China (2010CB951401);the National Natural Science Foundation of China (41171167 and 40871002)

摘　　要：High-resolution tree-ring δ18O chronologies covering the last millennium,although scarce,are essential in understanding patterns of climatic changes in the northeastern region of the Qinghai-Tibetan Plateau.For this study,a tree-ring δ18O chronology with a temporal resolution of 3-years was developed from the long-lived Qilian juniper(Sabina przewalskii Kom.),extending back in time to AD 991.This long δ18O chronology was significantly correlated with the yearly δ18O in tree rings during the common period from 1800 to 2006,and was an effective proxy for relative humidity during the growing season.A low-frequency moisture pattern signified the occurrence of a slight drought during the Medieval Climate Anomaly,a marked occurrence of a wet period during the Little Ice Age,and a trend in increasing moisture levels,although lower than average,alongside the Twentieth Century warming trend.Comparisons to other hydroclimatic reconstructions indicate that this tree-ring18O chronology serves as a reliable paleo-humidity proxy for the Qaidam Basin as well as documenting details of past humidity levels in the region.High-resolution tree-ring δ^18O chronologies covering the last millennium, although scarce, are essential in understanding patterns of climatic changes in the northeastern region of the Qinghai-Tibetan Plateau. For this study, a tree-ring δ^18Ochronology with a temporal resolution of 3-years was developed from the long-lived Qilian juniper （Sabina przewalskii Kom.）, extending back in time to AD 991. This long δ^18O chronology was significantly correlated with the yearly δ^18O in tree rings during the common period from 1800 to 2006, and was an effective proxy for relative humidity during the growing season. A low-frequency moisture pattern signified the occurrence of a slight drought during the Medieval Climate Anomaly, a marked occurrence of a wet period during the Little Ice Age, and a trend in increasing moisture levels, although lower than average, alongside the Twentieth Century warming trend. Comparisons to other hydroclimatic reconstructions indicate that this tree-ring δ^18O chronology serves as a relia- ble paleo-humidity proxy for the Qaidam Basin as well as documenting details of past humidity levels in the region.

关 键 词：树木年轮 柴达木盆地 湿度变化 时间分辨率 水分含量 气候变化 祁连圆柏 高分辨率 

分 类 号：P532[天文地球—古生物学与地层学]