Linking Glacier Retreat with Climate Change on the Tibetan Plateau through Satellite Remote Sensing

Abstract. Under global climate change, glaciers on the Tibetan Plateau are experiencing severe retreat, which significantly impacts the regional water cycle and the occurrence of natural hazards. However, detailed insights into the spatial-temporal patterns of this retreat and its climatic drivers remain insufficiently explored. In this study, an Adaptive Glacier Extraction Index (AGEI) is proposed based on analysis of multispectral Landsat images integrated with the Google Earth Engine, and comprehensive and high-resolution mapping of glaciers on the Tibetan Plateau is realized at five-year intervals from 1988 to 2022; subsequently, the ERA5-Land air temperature and precipitation data are downscaled to a finer 1-km resolution; finally, impacts of the annual and seasonal change of downscaled meteorological factors on the glacier retreat are quantified. Results demonstrated a rapid yet heterogeneous pattern of glacier retreat across the Tibetan Plateau between 1988 and 2022, with retreat rates ranging from 0.14 ± 0.07 % to 0.51 ± 0.09 % annually. A notable trend was observed where most glacier areas experienced a decrease from 1990 to 2000, followed by a slight increase. From 2010, a majority of the glaciers exhibited either a static state or minimal retreat. The most pronounced impact of annual temperature on glacier retreat is observed in Zone VIII, with a value of -9.34 × 10³ km²/°C, and the most restraining impact of precipitation on glacier retreat reaches 261 km²/m, which is observed in Zone VI for the spring season. Further, it identifies the influence of debris thickness on the glacier retreat rate. These insights are pivotal in comprehending the temporal and spatial heterogeneity of glacier retreats, and in understanding the effects of climatic variations on the state of glaciers on the Tibetan Plateau.