Current and Projected Changes in Lake Ice Phenology on the Tibetan Plateau: Impacts of Climate Change and Lake Expansion

In recent decades, the Tibetan Plateau has experienced a warmer and wetter climate. As a robust climate indicator, lake ice phenology responds sensitively to these changes. Beyond climate conditions, lake ice is also influenced by lake properties, which have also been changing rapidly. However, their impact on lake ice has been understudied due to limited data. Therefore, we used Advanced Microwave Scanning Radiometer 2 brightness temperature data and daily air temperature data to obtain the ice phenology for 182 lakes on the Tibetan Plateau from September 2012 to August 2022. Using this new data set, we examined the impacts of climate change and lake expansion on lake ice dynamics and their future changes. Our findings indicated that lake ice phenology on the Tibetan Plateau was strongly influenced by multiple factors. Freeze-up dates were primarily affected by lake properties such as latitude, volume, and area, whereas break-up dates were dominated by air temperature. Using random forest regression, we projected future declines in lake ice under the SSP126, SSP245, and SSP585 scenarios. Additionally, lake expansion could further delay freeze-up dates. By the end of this century, freeze-up dates are expected to be delayed by 3–11 days, while break-up dates could advance by 2–20 days, depending on the climate scenario. These findings highlight the urgent need to mitigate climate change to reduce lake ice loss on the Tibetan Plateau.