摘要
根据洱海湖泊沉积物有机碳稳定同位素记录，结合硅藻分析资料，恢复了近８ｋａ来云南洱海地区的气候演化序列。结果表明：８．１ｋａＢ．Ｐ．来的气候演化分为９个阶段，伴随湖泊水位波动变化。不同区域的全新世环境演化对比显示洱海气候演变主要受季风的强弱转换和时空变迁的控制，５．９ｋａＢ．Ｐ．以前气候偏暖，与太阳辐射增强引起的北半球季风环流加强有关。洱海湖泊沉积记录的暖（温）干期对应西南季风萎缩、东亚夏季风加强；相反，温（暖）湿期对应东亚夏季风减弱、西南季风加强。洱海湖泊沉积记录中三个冷事件出现在：７．２ｋａＢ．Ｐ．、５．３ｋａＢ．Ｐ．和３．７ｋａＢ．Ｐ．左右，冷干（湿）期受亚洲冬季风加强的影响。
Based on the data of organic carbon stable isotope ratios and diatoms,the sequences of climate evolution in the past 8ka years in Erhai Lake (in Yunnan Province)have been reconstructed.The results of the research indicate that the climate evolution in the past 8ka years can be devided into nine stages coinciding with lake level fluctuations.Comparisons of different regional environmental records indicate that the climate evolution was mainly controlled by the intensity and the temporal spatial changes of monsoon in southwest China.Before 5 9kaB.P.,the climate was inclined to warm temperate condition due to intensifications of solar radiation and monsoonal circulations in Northern Hemisphere.Organic carbon stable isotope ratios of lake sediment in Erhai Lake show that in warm or temperate dry stages southwest monsoon was weak and East Asian summer monsoon was intensified.On the contrary,in the conditions of temperate(warm) wet stages southwest monsoon was strong and summer monsoon was weak.There were three cold events in the records from Erhai Lake sediments,in 7 2kaB.P.,5 3kaB.P.and 3 7kaB.P. respectively.The cold dry or wet stages were affected by the intensification of Asian winter monsoon.
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
1998年第3期23-29,共7页
Marine Geology & Quaternary Geology
基金
国家自然科学基金
中科院湖沼专项资助
关键词
有机碳
稳定同位素
气候演化
洱海
云南
古气候
organic carbon stable isotope ratios lake sediments climate evolution Asian monsoon Erhai Lake
