论文部分内容阅读
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.
As an important atmospheric circulation system in the northern hemisphere, the Asian monsoons and westerlies are of great significance to the advance and retreat of the glaciers, the water balance and the changes of the ecological environment in the Qinghai-Tibet Plateau. Many researches have reconstructed the changes of their intensities. However, since the last ice- Intensity changes are still controversial.The records of the oxygen isotope records between the geogrid and the ichthyosphere Oxygen isotope records since the last ice-cooling period in the reconstruction of the core samples of the geo-lakes in the central Qinghai-Xizang Plateau show that the water level of geogrids is shallow and fluctuates frequently from 17 to 11.7 ka . The westerly winds are the main influencing factors of climate change. The environmental changes in the study area are closely related to the North Atlantic cold events. From 11.7 to 10ka, corresponding to the increase of the Indian monsoon, the water level of Gogo rises rapidly, the winter wind force becomes smaller and the Indian monsoon replaces the westerly winds After 10 ~ 8 ka, the water level of Ge Ge slightly decreased, which may correspond to the weakening of the Indian monsoon or the decrease of melting glaciers. After 8 ka, in response to the gradual decrease of the Indian monsoon, The westerly wind may be enhanced since the last ice retreat, and the succession history of the westerly and Indian monsoon strength since the last ice expiration can be summarized as follows: before 16.5 ka, mid-latitude westerly Most of the Qinghai-Tibet Plateau is controlled by the westerly wind and has a good coupling with the North Atlantic climate. The climate pattern of 16.5-15.5 ka is similar to today’s. The westerly wind controls the middle-northern part of the Qinghai-Tibet Plateau, while the southern part of the Qinghai-Tibetan Plateau The Indian monsoon has a greater impact. In the early Middle-Holocene, the solar radiation increased in summer and the Indian monsoon increased. In the late Holocene, the Indian monsoon weakened and the westerly wind affected the western and northern Qinghai-Tibet Plateau.