Bridging Timescales of Tibetan Plateau Environmental Change: An Integration of Earth System Modeling with Modern and Paleo- environmental Proxies

青藏高原是地球上最大的造山带高原，在近5000万年的大陆碰撞中形成。这个高海拔高原表面的形成是全球和区域气候变化以及海洋化学变化的原因。尽管具有重要意义，但青藏高原的形成过程及其形成过程中全球和区域气候的演变尚不清楚。在这项建议中，我们以我们以前在安第斯高原的相关工作为基础。我们的重点是量化全球和区域气候如何在千年（如末次盛冰期）到地质（~50 Ma）的时间尺度上响应青藏高原表面隆起。更具体地说，我们将验证如果印亚碰撞、新生代高原表面隆起和冰川作用是气候变化的原因，那么这些过程的适当参数化古气候模拟应该能够预测西藏代用数据（如土壤碳酸盐δ18O、湖泊气候档案）的观测变率，并量化高原不同时间尺度的古气候和古海拔历史。我们将通过将全球和区域古气候模式与古气候代理相结合来检验这一假设。这些实验将在高原环境变化的时空尺度上架起桥梁，从而形成了解高原现代和未来潜在气候变化的基线。

The Tibetan Plateau is the largest orogenic plateau on Earth and formed in response to continental collision over the last ~50 Million years. The formation of this high-elevation plateau surface is invoked for changes in global and regional climate, as well as in ocean chemistry. Despite their significance, the processes responsible for Tibetan Plateau formation and the evolution of global and regional climate during its formation are poorly resolved. In this proposal we build upon our previous related work on the Andean Plateau. Our focus is to quantify how global and regional climate have responded to Tibetan Plateau surface uplift over timescales ranging from millenial (e.g. last glacial maximum) to geologic (~50 Ma). More specifically, we will test the hypothesis that if Indo-Asian collision, Cenozoic plateau surface uplift, and glaciations are responsible for climate change, then appropriately parameterized paleoclimate simulations of these processes should predict the observed variability in Tibetan proxy data (e.g. δ18O in soil carbonates, lacustrine climate archives), and quantify the paleoclimate and paleoelevation history of the plateau over different time scales. We will test this hypothesis through an integration of global and regional paleoclimate models with paleoclimate proxies. These experiments will bridge spatial and temporal timescales of environmental change over the plateau thereby forming a baseline for understanding modern and potential future climate variability over the plateau.