青藏高原纳木错湖近150年来气候变化的湖泊沉积记录

高海拔地区的纳木错湖是研究过去气候环境变化的理想场所。本文结合附近气象站点实测数据与纳木错浅湖芯的研究结果，筛选出适用的气候环境代用指标，并对当地过去近150年来的气候变化记录进行重建。其结果显示，19世纪50年代至20世纪，以偏暖湿为主；20世纪初至20世纪50年代，该阶段气候总体上呈现出冷干特点，并从20世纪20年代左右逐渐向暖湿气候过渡；20世纪中叶至2005年，这期间气候有一定波动，但整体上以气温上升为主要趋势，在降水略减的情况下湖泊并未出现萎缩，表明气温升高可能导致冰川消融加快从而对入湖径流有一定补给作用。

A 150 Year Climate Change History Reconstructed by Lake Sediment of Nam Co,Tibetan Plateau

Nam  Co in high-altitude area is the ideal place to study the past climatic and environmental changes. In this paper, we tried to compare the measured lake sediment results of Nam Co with meteorological data in local stations and  chose  some proxies to reconstruct the climate and environment change record in the past 150 years in this area. The values of TOC, grain size, Sr/Ba and Rb/Sr had clear environment significance and reflected the climate change well. Geochemical multi-proxies of lake core NMC09 showed the final result  as follows, the climate was characterized with warm and humid from 1 850~1 900 A.D.. During the period of 1 900~1 950 A.D., it was a cold-wet period, and had transformed to the warm and humid period gradually since 1920s. After the 1950s it had main trend of rising temperature although it had a little climate fluctuations, and the lake did not shrink obviously in spite of reduced precipitation. It suggested that rising temperature could lead to glacier melting accelerated to supply the run-off into Nam Co.