青藏高原隆升与新特提斯海退却对亚洲中纬度阶段性气候干旱的影响

Effects of the Uplift of the Tibetan Plateau and Retreat of Neotethys Ocean on the Stepwise Aridification of Mid-latitude Asian Interior

亚洲内陆是北半球最大、最广阔的中纬度干旱区,且不同于世界上分布于副热带高压控制下的干旱区。现今的亚洲中纬度干旱区深居内陆,远离各大洋的水汽来源。亚洲中纬度干旱区究竟如何形成?历经了怎样的干旱化过程?其形成演化的动力机制是什么?这些一直是悬而未决的问题。事实上,亚洲中纬度干旱区发展成今天所见的干旱荒漠,并不是短时间内实现的,而是经历了漫长的阶段性演化进程,是在新生代以来印度、阿拉伯、非洲板块与欧亚大陆的碰撞,青藏高原的隆升,新特提斯海的退却以及新生代全球气候变冷与海平面下降等区域和全球要素共同作用下,从半湿润—半干旱—干旱—极端干旱渐进演化而来。历经了始新世的半湿润气候,渐新世的半湿润-半干旱气候和中新世末期以来的干旱-极端干旱气候。

The Asian interior is the largest mid-latitude arid zone in the Northern Hemisphere, being different from the other arid areas controlled by the Subtropical High. The present Asian mid-latitude situates in the heart of the Eurasia, being far away from any of the ocean＇s moisture sources. How exactly does the mid-latitude Asia become a vast arid area？ What kinds of arid processes have been experienced？ How is about the mechanism of its formation and evolution？ All these issues are unsolved questions. Actually, the present desert environment of the mid-latitude Asia is not a result of short time evolution, but that of long-term stepwise aridification processes. The collision between the Africa Plate, Arabian Plate, and Indian Plate with the Eurasian Plate, the uplift of the Tibetan Plateau, the shrinkage of the Neotethys, and the eustatic global sea-level decline driving by Cenozoic global cooling have all involved in the aridification processes. The mid-latitude experienced Eocene sub-humid, Oligocene sub-humid to semi-arid, and the arid to extreme arid climate since the latest Miocene.