Loess Recorded Climatic Change During The Last Glaciation On The Eastern Tibetan Plateau, Western Sichuan

High-resolution paleoclimatic records of the Greenland ice cores and North Atlantic deep sea sediments revealed the general high-frequency instability of Late Pleistocene climate. Recently, increasing geological evidences from several areas outside the North Atlantic have shown that the millennial scale warmings and coolings have global signatures. Understanding forcing mechanism of these rapid climatic oscillations(D /O cycle and Heinrich events), effects of these rapid climatic oscillations to other parts' climate, environment and ecology of the Northern hemisphere and the way to these effects still requires global extended investigations of these events in various high-resolution climate records, then profoundly compare them temporally and spatially.Based on the grain size, magnetic susceptibility, color and carbonate analysis of 3000 samples from 13 loess profiles on the western Sichuan Plateau, we find all profiles generally record climatic change during the last glaciation. But Zhangla profile record the most rapid climatic oscillations during the last glaciation. Based on Zhangla profile 11.5 m section of L1, We present rapid climatic oscillations and climatic change process during last glaciation on the eastern Tibetan Plateau, western Sichuan.In the eastern Tibetan Plateau, loess mainly comes from Tibetan plateau and is transformed by westerly wind circulation. Grain size of loess on this area mainly indicts the power of the upper-level westerly wind. Upper-level westerly wind change bears a high similarity toδ¹⁸O record from North Greenland Ice Core. Upper-level westerly wind also show many rapid oscillations during the Last glaciation. Meanwhile, generally power of upper-level westerly wind is also affected by Tibetan Plateau surface condition.In the eastern Tibetan Plateau, precipitation mainly comes from the Indian Ocean, controlled by southwest monsoon strength. So the color of the Loess in this area mainly reflects the strength of the southwest monsoon. Analysis of loess color a * of the Zhangla profile shows that the southwest monsoon also bears a high similarity to stalagmites record from Nanjing Cave. The southwest monsoon shows many rapid oscillations during the Last glaciation. Meanwhile, the southwest monsoon is also affected by global ice volume in generall.The above facts show that the eastern Tibetan plateau is affected by the upper-level westerly wind and the Indian summer monsoon. At the same time, the upper-level westerly wind and the Indian summer monsoon are affected by the North Atlantic thermohaline circulation. Meanwhile they affect the eastern Tibetan plateau through material and energy exchange of complicatedly atmospheric and ocean circulation.