泥炭记录的新疆阿勒泰地区全新世气候变化历史研究

Understanding the natural trend and rhythms of the Holocene climate changes is prerequisite for understanding the present and future natural and human-induced climatic changes. Climatologically, the Altai Mountains are important because it is the battlefield between the Westerlies and the East Asian Monsoons. Furthermore, the ubiquitously-distributed thick peat mantles (3-5m thick) that initiated around 10,000 yr BP and the ideal C-14 dating targets assured our confidence that the high-resolution climatic changes of the Holocene can be reliably reconstructed. The project plans to reconstruct the climatic changes of the Holocene in the study area through following steps. First, establish a reliable age-depth model basing on plants cellulose AMS 14C dates. Second, Comprehensive analysis of climate proxies which mainly including Humification, Plant cellulose and Long-chain alkanes carbon isotope. Third, high resolution climatic variations reconstruction. Finally, attempt to improve our understanding of large-scale climatic patterns and the driving mechanisms.

全新世气候变化规律的研究被认为是预测未来气候变化的前提。本项目选取对气候变化敏感的新疆阿勒泰地区（“西风”和“东亚季风”相互作用区）作为研究区域，选取沉积速率高、沉积连续且测年材料丰富的泥炭沉积作为研究对象，在可靠的年代（植物纤维素AMS 14C测年）基础之上，综合多指标（腐殖化度、植物纤维素碳同位素、长链烷烃种类以及单烃碳同位素）分析，力求高分辨率的重建新疆阿勒泰地区全新世气候变化历史，进行区域对比研究，深入分析研究区全新世气候变化的驱动机制。弄清研究区全新世以来“西风”和“东亚季风”相互作用历史，理解研究区全新世气候变化对全球变化（高低纬度以及北大西洋地区全新世气候变化）的区域响应。

全新世气候变化的研究被认为是预测未来气候变化的前提。本项目选取对气候变化敏感的新疆阿勒泰地区作为研究区域，选取沉积速率高、沉积连续且测年材料丰富的泥炭沉积作为研究对象，在可靠的年代（植物纤维素AMS14C测年）基础之上，综合多指标分析，高分辨率地重建了研究区全新世气候变化历史。区域对比以及驱动机制研究显示：阿勒泰地区全新世以来主要受西风带控制，降水模式遵循西风模式，即早全新世气候干旱而晚全新世气候湿润；温度重建显示研究区全新世温度变化趋势与北半球周边地区一致，大致遵循早全新世温度上升而晚全新世温度降低的规律，总体受控于北半球夏季太阳辐射；在千年时间尺度上研究区的水-热组合基本遵循于暖干—冷湿的模式。我们的研究结果对于全面理解研究区全新世气候变化对全球变化的区域响应有着重要的参考意义。