Session: Warm Climates (Mid-Holocene, Last interglacial, Deep-time, Pliocene)
Author: Xiangyu Li / xiangyuli07@hotmail.com / Institute of Atmospheric Physics,CAS
Co-author: Ran Zhang, Institute of Atmospheric Physics,CAS;
                    Zhongshi Zhang, Department of Atmospheric Science, School of Environmental Studies, China University of Geosciences (Wuhan); Uni Research Climate, Uni Research and Bjerknes Centre for Climate Research;
                    Qing Yan, Institute of Atmospheric Physics,CAS;

Abstract:
Evolution of the aridity in the Asian inland is now a hot topic in the study of the Cenozoic climate in Asia. Recent geological evidence has pushed the earliest Cenozoic Asian inland aridification back to the Eocene. This enhanced Eocene aridity in the Asian inland is related to combined impacts from global cooling, topography uplift and land–sea reorganization. It was widely believed that global cooling led to this aridification. Here, we carry out climate simulations to demonstrate that the early uplift of Tibetan Plateau is also important in the enhanced Asian inland aridity during Eocene. Our simulations support the observed enhanced Asian inland aridity during Eocene observed from geological evidence. Both the early uplift of Tibetan Plateau global cooling induced by decrease in atmospheric CO2 concentration contribute to the enhanced Asian inland aridity, while changes in land–sea distribution do not. The early uplift of the Tibetan Plateau contributed to the long-term Asian inland aridification during the Eocene, whilst the variations in the atmospheric CO2 concentration are more important in modulating the regional aridity on short timescale.