Spatiotemporal variation characteristics of snowfall-precipitation ratio on the Tibetan Plateau

This study investigates the variations in precipitation phases on the Tibetan Plateau (TP) from 1979 to 2020. Utilizing the Third Pole region′s high-resolution (1/30°, daily) surface meteorological data (TPMFD) and a method based on elevation and meteorological conditions, we analyzed the snowfall-precipitation ratio (SPR) spatiotemporal characteristics on the TP. Key findings include: ① Significant spatial differences in SPR, with higher values in the west and lower in the east. ② An overall downward trend in SPR, decreasing at an average rate of 1.11% per decade (p < 0.001). ③ Both cold and warm seasons exhibit increases in rainfall and decreases in snowfall and SPR. However, the rates of change are more pronounced in the warm season. ④ Snowfall is comparable in the cold and warm seasons in the east and west of the plateau. In contrast, the central plateau experiences predominant snowfall during the warm season. About 90% of the annual rainfall occurs in the warm season, and the proportion of warm season snowfall to annual snowfall is decreasing (-0.29% per decade) in most plateau regions. These findings provide valuable insights for regional climate change and water science research.