晚新生代东亚气候变化: 进展与问题

Abstract

Climate in Eastern Asia is composed of monsoon climate in the east, arid and semi-arid climate in the north and west, and the cold and dry climate of Qinghai-Tibetan Plateau in the southwest. The underlying causes for the evolution of East Asian climate during late Cenozoic have long been investigated and debated, particularly with regards to the role played by the Qinghai-Tibetan Plateau uplift and the global cooling. In this paper, we reviewed major research developments in this area, and summarized the important results. Based on a synthesis of data, we propose that the Qinghai-Tibetan Plateau uplift alone cannot fully explain the formation of monsoon and arid climates in Eastern Asia during the past 22–25 Ma. Other factors such as the global ice volume and high-latitude temperature changes have also played a vital role. Moreover, atmospheric CO2 changes may have modulated the monsoon and dry climate changes by affecting the location of the inter-tropical convergence zone (ITCZ), which controls the monsoon precipitation zone and the track of the East Asian winter monsoon during late Cenozoic. The integration of high-resolution geological record and numerical paleoclimate modeling could make new contributions to understanding the climate evolution and variation in eastern Asia in future studies. It could facilitate the investigation of the regional differences in East Asian environmental changes and the asynchronous nature between the uplift of Qinghai-Tibetan Plateau and their climatic effects. These would be the keys to understanding underlying driving forces for the evolution of the East Asian climate.