Spatiotemporal Characteristics of Snow Cover and Its Climate Impacts in the Western Tibetan Plateau Region

The western Tibetan Plateau (WTP; west of 80˚E) represents a distinct geographical domain bounded by the Pamir Plateau, Karakoram Range, and Hindu Kush mountains. Characterized by perennial snow cover, this region plays a critical role in global and regional climate systems while serving as a vital freshwater reservoir for over 400 million people across the Indus, Amu Darya, and Tarim River basins. This study investigates spatiotemporal variations in snow cover fraction (SCF) and snow depth (SD) across the WTP from 1978 to 2020 using weekly snow cover data from the National Snow and Ice Data Center (NSIDC) and daily snow depth records from the National Tibet Plateau Data Center (TPDC). Results showed a significant decline in SCF at rates of −0.17% and −0.93% 10 a−1 during spring and summer, respectively, alongside a springtime reduction (−0.02 cm 10 a−1) and slightly increase in summer (0.001 cm 10 a−1) SD. These trends are attributed to rising seasonal temperatures (0.04˚C and 0.02˚C 10 a−1) and shifts in precipitation patterns (−0.16 mm and +0.04 mm 10 a−1) in the same season. Correlation analyses identify that the ENSO IOBW, and TIOD show positive relationship with SCF reductions, while the NAO and SIOD show negative correlation. These findings underscore the sensitivity of WTP snow cover to climatic drivers and water resource management for downstream regions in South and East Asia.