广东现代樟树树轮纤维素的碳同位素与厄尔尼诺事件的关系

The δ^(13)C Sequence of Cinnamomum Camphora Tree Ring α-cellulose in Yangchun County,Guangdong Province,and Its Relationship with the El Nio Event

本文对广东阳春河的樟树树轮纤维素Δδ13 C序列研究发现 ,厄尔尼诺对树轮C同位素的高频变化的影响有一定的滞后性 ,一般是厄尔尼诺强度高峰期所对应年的下一年树轮Δδ13 C值较低。通过谱分析发现 ,树轮记录的Δδ13 C序列变化中2～ 3a周期与热带气候的“准两年振荡”(QBO)十分一致 ,这从另一个侧面说明了广东樟树树轮记录了大范围的ENSO信息。其中准 4 .5 7a周期可能与影响全球气候异常的厄尔尼诺事件的周期有关 ,很可能就是厄尔尼诺事件引起的气候变化对树木生长影响的反映。研究表明 ,广东厄尔尼诺所引起的气候变化 ,在树轮同位素中有较好的记录。说明在热湿地区 ,冬季树木仍有同位素分馏 ,树轮δ13

The authors measured the tree ring α-cellulose δ 13C time series in Yangchun County, Guangdong Province. By spectrum analysis, the variation of tree-ring δ 13C sequence shows a quasi periodicity of 2～3 a ,which is coincident with “quasi two-year tropic barometric oscillation” (QBO)and demonstrates that the tree ring in Guangdong Province can record large-scale information of ENSO. Quasi periodicity of 4.57 a is correlated with the global standard periodicity of El Nio.The results indicate that the high-frequency oscillation of tree ring δ 13C sequence in this area is related to El Nio, temperature, rainfall and Asiatic monsoon. The climate change resulting from El Nio can be better recorded in isotopes of tree ring. In the warm and humid area the advantage of tree ring isotope lies in the fact that δ 13C can still record the effects of winter temperature and Asiatic monsoon.