Progress in palaeoclimate research on the Tibet Plateau based on ice core records

Abstract

Ice core is an important information carrier to reconstruct paleoclimate. Because of its high resolution,high fidelity,huge amount of information and long time scale,it has become a research hot spot. Since the first ice core was found in Qilian Mountain in 1986,in China many other ice cores have been successively drilled in Tibet Plateau,such as Guliya,Malan,Dasuopu,Puruogangri,Dongrongbu and so on. In this paper,we provided a review and summary of study results with the ice cores mentioned above,and discussed the approaches and indicators of ice cores as information carriers reflecting paleoclimate,shown as follows.(1) The significant corresponding relationship between Oxygen isotope and temperature: Oxygen isotope shows a positive correlation with temperature though it is affected by "amount effect of precipitation water" in the southern part of the Tibet Plateau.(2) The relationship between accumulation of ice core and precipitation: accumulation of ice core can be used as a direct record of glacial precipitation,and,at the same time,the amount of accumulation indicates climate change in the past.(3) The relationship between atmospheric aerosols and climate environment:the climate environment reveals the changing history of atmospheric aerosols and helps understand the geomorphological evolution and intensity changes of atmospheric circulation of the surrounding areas on the Tibet Plateau in the past.(4) The relationship between trace elements and paleoclimate: trace elements can be used to explore the connection between ice core records and solar active rhythm. It also indicates the influence of industrial pollution on glacier environment in the high altitude.(5) The relationship between ice core inclusions and paleoenvironment: ice core inclusions are the complete preservation of ancient atmosphere,and can be used for comparing and reconstructing the ancient atmospheric composition from different historical stages and reflecting the information of environmental changes of this region in the long time.(6) The relationship between microorganisms in the ice core and the ancient environment: microorganisms in the ice core record the response to the environmental change in the past through its own unique biological characteristics. Microorganisms of different depths reflect the environmental conditions in different periods. Then,we presented the response of the ice core in Tibet Plateau to paleoclimates,including some extreme climate events in the past,the Medieval Warm Period,the Little Ice Age,glacial-interglacial cycles,ENSO events,solar activity patterns and global warming since the Industrial Revolution,but the Tibet Plateau's response mechanism is not the same as that of polar regions. It has its own characteristics. We also explained the similarities and differences of the ice core in the reconstruction of paleoclimate under the influence of different monsoon systems because of the mutual influences of Indian monsoon,East Asia monsoon and the west wind on the Tibet Plateau. Finally,based on the current research status,we presented in-depth discussions on the prospects of the research such as: strengthening innovation in interdisciplinary studies,use of new technologies,development of alternative indicators,influence of the ice core record on factor assessment,creation of quantitative models,and other future directions.