Comparison of Cenozoic surface uplift and glacial-interglacial cycles on Himalaya-Tibet paleo-climate: Insights from a regional climate model

Abstract. Assessing paleo-climatic changes across the Tibetan Plateau and the underlying driving mechanisms provides insights for the natural variability in the Earth's climate system in response to tectonic processes and global climate change. In this study, we use a high-resolution regional climate model to investigate various episodes of distinct climate states over the Tibetan Plateau region during the Cenozoic rise of the Plateau and Quaternary glacial/interglacial cycles. The main objective is to compare climate changes during the Miocene-Pliocene uplift period with climate anomalies during the last glacial maximum and the mid-Holocene optimum, based on a consistent modeling framework.

Reduced plateau elevation leads to regionally differentiated patterns of higher temperature and lower precipitation amount on the plateau itself, whereas surrounding regions are subject to colder conditions. In particular, Central Asia receives much more precipitation prior to the uplift, mainly due to a shift of the stationary wave train over Eurasia. Cluster analysis indicates that the continental-desert type climate, which is widespread over Central Asia today, appears with the Tibetan Plateau reaching 50 % of its present-day elevation.

The mid-Holocene is characterized by slightly colder temperatures, and the last glacial maximum by considerably colder conditions over most of central and southern Asia. Precipitation anomalies during these episodes are less pronounced and spatially heterogeneous over the Tibetan Plateau. The simulated changes are in good agreement with available paleo-climatic reconstructions from proxy data. The present-day climate classification is only slightly sensitive to the changed boundary conditions in the Quaternary Quaternary. It is shown that in some regions of the Tibetan Plateau the climate anomalies during the Quaternary Quaternary have been as strong as the changes occurring during the uplift period.