令戈错湖芯重建过去17ka青藏高原大气环流变化

发布时间：2018-03-03 19:16

本文选题：末次冰消期　切入点：粒度　出处：《科学通报》2016年33期 　论文类型：期刊论文

【摘要】：亚洲季风和西风作为北半球重要的大气环流系统,对青藏高原冰川进退、水量平衡及生态环境变化具有重要意义.大量研究重建了两者的强弱变化,但是末次冰消期以来,西风与亚洲季风强度变化仍然存在争议.青藏高原中部令戈错湖泊岩芯样品重建的末次冰消期以来令戈错粒度与介形虫氧同位素记录表明,17~11.7 ka,令戈错水位较浅且波动频繁,西风是气候变化的主要影响因素,研究区环境变化与北大西洋冷事件关系密切;11.7~10ka,对应于印度季风的增强,令戈错水位迅速升高,冬季风力变小,印度季风取代西风成为控制环境变化的主要因素;10~8 ka之后,令戈错水位略有降低,可能对应于印度季风的减弱或者冰川融水的减少;8 ka之后,响应于印度季风逐渐减小,令戈错逐渐萎缩,西风可能存在增强.末次冰消期以来西风与印度季风强弱演替历史可以归纳为:16.5 ka之前,中纬度西风强盛,青藏高原大部分区域均由西风控制,与北大西洋气候变化表现出较好的耦合关系;16.5~11.5 ka气候格局与现今类似,西风控制着青藏高原中-北部地区,而青藏高原南部受印度季风影响更大.早中全新世,夏季太阳辐射增加,印度季风增强;晚全新世,印度季风减弱,西风可能对青藏高原西部以及北部存在影响.
[Abstract]:As an important atmospheric circulation system in the Northern Hemisphere, Asian monsoon and westerly are of great significance for glacier advance and retreat, water balance and ecological environment change over the Qinghai-Xizang Plateau. The variation of the intensity of westerly and Asian monsoon is still controversial. The grain size and oxygen isotopic records of ostracoda in the core of Linggocha lake in central Qinghai-Xizang Plateau since the last ice elimination period show that the water level of Gejiao is shallow and fluctuates frequently. The westerly wind is the main influence factor of climate change. The environmental change in the study area is closely related to the cold events in the North Atlantic, corresponding to the strengthening of the Indian monsoon, which makes the Gobo water level rise rapidly and the wind intensity decrease in winter. After the Indian monsoon replaced the westerly wind as the main factor to control the environmental change, the Gobo water level decreased slightly after 108ka, which may correspond to the weakening of the Indian monsoon or the decrease of glacial melt water, which is in response to the gradual decrease of the Indian monsoon. Since the last ice extinction period, the succession history of the west wind and the Indian monsoon strength and weakness can be summed up as: before 1: 16.5 ka, the mid-latitude westerly was strong, and most areas of the Qinghai-Xizang Plateau were controlled by the west wind. There is a good coupling relationship with climate change in the North Atlantic. The climatic pattern is similar to that of the present one. The westerly wind controls the central and northern regions of the Tibetan Plateau, while the southern part of the Tibetan Plateau is more affected by the Indian monsoon. The summer solar radiation increases and the Indian monsoon intensifies, and in the late Holocene, the Indian monsoon weakens, and the westerly wind may have an impact on the western and northern parts of the Qinghai-Xizang Plateau.
【作者单位】：中国地质大学地球科学学院;中国科学院青藏高原研究所环境变化与地表过程重点实验室;Large
【基金】：中国科学院战略性先导科技研究计划B类项目(XDB01020300) 国家自然科学基金(41230523)资助
【分类号】：P532

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