湖光岩玛珥湖硅藻记录重建全新世高分辨率东亚冬季风演化历史

The East Asian winter monsoon (EAWM) not only plays an important role within the Asian climate system, but also acts as a link between the polar and tropical climate systems. It is necessary therefore for us to improve our knowledge of the EAWM in order to understand climate dynamics in this vast region. Although the abrupt climate changes of the Holocene period have been received considerable attention, the relationship between the EAWM and the abrupt climate changes observed in high latitude so far is not clear. Recently, the diatoms from Huguangyan maar lake have been developed to be a good index for the EAWM. In this project, we will try to reconstruct the variation of the EAWM during the Holocene by using diatom as an indicator and depending on AMS14C chronology. We will discuss the relationship between the EAWM and the abrupt climate changes. We will also discuss the correlation between the EAWM and East Asian summer monsoon (EASM) by comparing the diatom records from Huguangyan maar lake with the stalagmite records from Hulu and Dongge cave. The project will provide the new evidence for the variation of the EAWM through the Holocene for understanding the mechanism of paleoclimate changes.

东亚冬季风是连接北半球高纬气候过程和低纬度气候变化的重要纽带，甚至影响南半球的气候变化。因此，研究东亚冬季风的演化历史有助于理解全球气候变化的动力机制。全新世时期发生了一系列千年尺度的气候突变事件，高分辨率的东亚冬季风变化历史是否能和这些千年尺度的变化进行对比，是探讨千年尺度气候变化全球一致性以及理解亚洲季风动力机制的关键。已有研究发现广东湛江湖光岩玛珥湖的硅藻是很好的冬季风代用指标。本项目拟开展1万年来湖光岩玛珥湖高分辨率的硅藻研究，通过放射性同位素测年建立精确的年代标尺，重建10-20年高分辨率的冬季风演化历史，探讨全新世千年尺度气候变化的全球可对比性。通过与高分辨率的石笋氧同位素记录对比分析，研究东亚冬季风与东亚夏季风的关系，为探讨古气候变化的动力机制提供新的高分辨率的全新世东亚冬季风的证据。

东亚冬季风不仅在亚洲气候系统内起到重要的作用，而且把北极高纬度的冷空气带到低纬，跨越赤道，输送到南半球，汇入澳大利亚季风系统，是连接极地与热带气候系统的重要纽带。了解东亚冬季风的演化过程将有助于理解东亚季风系统及全球气候变化的动力机制。已有研究发现广东湛江湖光岩玛珥湖的硅藻组合是很好的冬季风代用指标，在全新世时期轨道尺度上，东亚冬季风与东亚夏季风处于同相位变化，在末次冰期向全新世过度的千年尺度上，东亚冬季风与夏季风互为反相位。本项目开展了全新世时期湖光岩玛珥湖高分辨率的硅藻组合研究，通过放射性同位素测年建立精确的年代标尺，重建年高分辨率的东亚冬季风演化历史，探讨全新世千年尺度气候变化的全球可对比性。