Volume estimation and dynamics of the Purog Kangri ice field on the inner Tibetan Plateau

Study region Purog Kangri ice field, inner Tibetan Plateau. Study focus Due to limited field observations on extreme-glaciers, detailed insights into the ice thickness distribution, spatio-temporal patterns of glacier variation and its climatic drivers of such glaciers remain insufficiently scrutinized. This investigation mapped the ice thickness distribution of the Purog Kangri ice field by an improved distributed glacier thickness model and noted recent dynamism concerning its surface elevation and glacier surge episodes. This dynamism was subsequently connected to proximate climatic shifts and broad-scale atmospheric circulation configurations. New hydrologic Insights The ice field retreated from 427.65 ± 5.27 km 2 in 1974 to 389.64 ± 5.58 km 2 in 2021 (0.19 % a −1 ). Digital elevation model differencing quantified a marginal mass deficit of −0.13 ± 0.01 m a −1 or −0.11 ± 0.02 m w.e.a −1 since 1974. The mass loss rates varied across different periods, showing an accelerating trend since 2012. We also identified four surge-type glaciers and reported observations of their surge behavior. Employing a perfect-plasticity framework, the aggregate volume estimation for the ice field in 2021 was established at 43.11 ± 17.82 km³ , signifying a mean ice thickness of 108.73 ± 17.1 m. The findings indicated that the spatial-temporal patterns of Purog Kangri ice field variation can be explained by the regional climate change. From the perspective of large‑scale circulation, the change in geopotential height and the cyclonic/anti-cyclonic circulation exhibited opposite spatial patterns during 1974–2000 and 2001–2021, which are associated with variations of the ice field. Our results deepen understanding of the response mechanisms of extreme-glaciers to climate change and provide a quantitative basis for predicting regional hydrological processes and ecosystem evolution in the inner Tibetan Plateau.