印度洋东部与南海南部沉积孢粉记录的季风信息及相互关联

Asian monsoon is the most active and important member of the global monsoon. Currently, researches on the interrelation between the Indian monsoon and East Asian Monsoon are still lagging behind. In this study, we are adopted by pollen analysis of four cores sediment of the eastern Indian Ocean and the southern South China Sea, based on more accurate and unified AMSC14 dating. Some specific types of pollen will be used as winter and summer monsoon proxy indicator, combined with East Asia and Australia Surface pollen database, the change of pollen terrestrial sources will be discussed. According to changes in terrestrial sources, the change frequency of Asian monsoon and monsoon currents will be discussed respectively. The information of climate events on the scale of thousands year will be achieved based on pollen percentage. The information of change of rivers and climate humid will be achieved based on the pollen concentration. Change of climate humid and transformative distance will be discussed from the nature fire based on the charcoal information. The vegetation types in the past will be reconstructed based pollen assemblage, thus people will know if there was a savanna corridor during the Last Glacial Maximum. From above works, the continuous, high-resolution sequences of changes in India winter，summer monsoon and East Asian winter, summer monsoon were established since 46ka BP. The monsoon frequency, period and intensity that had been reflected from the sequences of the Indian monsoon and East Asian monsoon will be compared. Based on this study, the dynamic mechanism of the Indian monsoon and East Asian monsoon will be explored and validated from the perspective of marine sediments. It will help to improve and perfect the theory of global monsoon system.

亚洲季风是全球季风最活跃和最重要的成员。目前针对印度季风与东亚季风相互关系的研究仍相对滞后。本研究拟通过印度洋东部和南海南部4个沉积岩芯的孢粉分析，基于较精确而统一的AMS14C测年，以孢粉特有类型作为冬夏季风的代用指标；结合陆地表土孢粉数据库，获得陆源地信息；通过孢粉陆源区的变化获得季风和洋流的变化信息；通过孢粉百分比获得千年尺度气候事件的发生信息；通过孢粉浓度获得径流变化和干湿交替的信息；通过炭屑指示的陆源地天然火信息推测气候的干湿和传播距离变化；以孢粉组合重建末次盛冰期陆源地的植被类型，判断巽他古陆是否有热带稀树草原分布。通过上述工作构建约46ka以来亚洲冬夏季风在印度洋东部与南海南部较为连续、详细的历史演化序列；并对比印度洋季风和东亚季风爆发频率、周期、幅度及其相互关联，从海洋沉积的角度探讨和验证亚洲季风46ka以来的变化规律和动力机制。该结果将有助于推进对全球季风的认识。

亚洲季风是全球季风最活跃和最重要的成员。目前针对印度季风与东亚季风相互关系的研究仍相对滞后。本研究拟通过印度洋东部和南海南部4个沉积岩芯的孢粉分析，基于较精确而统一的AMS14C测年，以孢粉特有类型作为冬夏季风的代用指标；结合陆地表土孢粉数据库，获得陆源地信息；通过孢粉陆源区的变化获得季风和洋流的变化信息；通过孢粉百分比获得千年尺度气候事件的发生信息；通过孢粉浓度获得径流变化和干湿交替的信息；通过炭屑指示的陆源地天然火信息推测气候的干湿和传播距离变化；以孢粉组合重建末次盛冰期陆源地的植被类型，判断巽他古陆是否有热带稀树草原分布。该课题通过对南沙海槽及其邻近碳酸盐台地的海底沉积物柱状岩芯NS93-5和NS07-25孔样品的高分辨率的孢粉指标的综合测试分析，以及印度洋12I712 孔和YDY01、YDY09 钻孔的孢粉植硅体、碳屑等研究分别建立了东亚季风和印度洋季风演化序列，初步发现西太-东印暖池可以在南海和印度洋同时作为气候湿度指数，松花粉可作为海平面变化的指标，东北印度洋松花粉的百分比在低海平面期增加，与南海的情况相反，可能与二者的陆架的面积大小有关。发现末次冰消期以来的南亚季风和东亚季风都具有500年的周期。通过上述工作构建约46ka以来亚洲冬夏季风在印度洋东部与南海南部较为连续、详细的历史演化序列；并对比印度洋季风和东亚季风爆发频率、周期、幅度及其相互关联，从海洋沉积的角度探讨和验证亚洲季风46ka以来的变化规律和动力机制。该结果将有助于推进对全球季风的认识。