Dynamic glaciers improve LGM simulation in High Mountain Asia

<p>Glaciers on Tibetan Plateau and its surrounding areas were much more extensive during Last Glacial Maximum (LGM) when global mean temperature was 5-8 K lower than today. Accurately reconstructing glaciers on and around Tibetan Plateau remains vital towards understanding glaciers’ sensitivity against climate change, and vice versa.</p><p>Previous simulations on glaciers in High Mountain Asia during LGM are usually forced with prescribed climatology without considering the bi-directional feedbacks. We instead coupled a climate model (CESM) to an ice-sheet model (ISSM). Our results show that the interactions between HMA glaciers and climate was significant. Uncoupled runs that ignore such interaction yielded glacial coverage roughly 10% more than coupled runs. Regional glacial features change considerably in coupled simulation. Glaciers on the mid-west Tibetan Plateau decreased while those in Qilian Mountains, Tianshan Mountains and Pamir Plateau saw pronounced increase. Compared with uncoupled simulations, our coupled results is in better agreement with reconstructions of LGM glaciers.</p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p>KEY WORDS: Glacier; Ice-sheet; Tibetan Plateau; High Mountain Asia; Numerical simulation; Climate modelling</p><p> </p>