树轮δ13C记录的阿勒泰地区近160a夏季气温变化

摘要

In this paper, we developed 3 tree-ring width and δ13C chronologies of larch (Larix sibirica Ledeb.) on the southern slopes of Altai Mountains based on standard dendrochronology methods and stable carbon isotope research process. Correlation analysis indicated that the δ13C series is strong positive correlated with mean temperature. The δ13C series of tree rings response to July temperature is the strongest (r=0.608,p<0.0001)and the primary factor that control δ13C of larch(Larix sibirica Ledeb.)fractionation is the temperature in July. The summer temperatures can be reconstructed based on δ13C and meteorological data in Altay. In recent 160 years,the summer temperature rised slowly at the end of 19 century, and higher at the early 20 century. It obviously decreased from 1940s until 1960s and the period of 1960s was relatively cool summer in past 160a. After 1960s,the summer temperature has experienced the longest and most obvious warming period in the past 160 years on the southern slopes of Altai Mountains. The summer temperature that we reconstructed can not only represent the summer temperature changes in Altai Mountains, but also a large-scale region, include northern Xinjiang, southern Central Asia and Southern Russia.%利用阿尔泰山南坡东中西部3个采点的西伯利亚落叶松树轮样本，建立了3个树轮δ13C序列，结合阿勒泰地区6个气象站的气象资料，分析了阿尔泰山树轮δ13C对气候的响应，并重建了阿勒泰地区过去160 a夏季气温变化。研究表明，位于阿勒泰科勒迭难布拉克森林上线的树轮δ13C序列对阿勒泰地区夏季气温响应较好，与7月平均气温明显正相关，相关系数达到0.608（p<0.0001）；利用树轮δ13C可较好的重建阿勒泰地区过去160 a的夏季气温；近160年来，阿勒泰地区夏季温度19世纪末有缓慢上升趋势，20世纪初，夏季温度整体偏高，40年代以后，夏季温度明显下降，直到60年代，60年代成为近160 a夏季温度最低的时期，60年代至今，阿尔泰山南坡夏季气温经历了160 a来最长和最为强烈的升温时期。虽然有气象观测记录以来，阿勒泰地区夏季气温升温明显，但是20世纪初夏季温度要高于近30 a平均气温；重建的阿勒泰地区夏季温度序列不仅能代表整个阿尔泰山夏季温度变化，也能够较好的代表包括北疆、中亚部分地区和俄罗斯南部大范围的夏季温度变化。