As a natural solid reservoir, mountain snow is an important part of water resources, providing fresh water for two billion people in the world. High Mountain Asia (HMA) is an important distribution area of snow in the middle- and low- latitude mountains. In the past half-century, warming trend in HMA is obvious, and the increase of temperature breaks the original natural balance.
Previous studies have revealed the snowfall change mechanism in HMA under global climate change.
Researchers from the Xinjiang Institute of Ecology and Geography (XIEG) of the Chinese Academy of Sciences evaluated the projected changes in mean snowfall, snowfall days, and snowfall fraction for the years 2070-2099 relative to 1976-2005, under the Representative Concentration Pathway 4.5 (RCP4.5) and 8.5 (RCP8.5) emission scenarios.
The results showed that while NASA's NEX-GDDP (National Aeronautics and Space Administration Earth Exchange Global Daily Downscaled Projections) high-resolution daily downscaled dataset could successfully capture the distribution of mean snowfall climatology, it had a strong bias for extreme snowfall indices.
In general, the projected increase of temperature under RCP4.5 and RCP8.5 - especially in winter - would result in a decrease in snowfall amount (-18.9%, -32.8%), fewer snowfall days (-29.6%, -47.3%), and less precipitation falling as snow (-26.7%, -42.3%).
Furthermore, under high emission scenarios, rain-dominated regions were projected to expand 53.9%, while snow-dominated areas would only account for 17.9% of the entire HMA. Spatially, snowfall showed a more robust decline in eastern HMA (e.g., East Tienshan, East Kun Lun, Qilian, South and Eastern Tibet, and Hengduan) than in western HMA (e.g., Hissar Alay, Pamir, and Karakoram). This difference can be attributed to various environmental factors, such as climatology, elevation influences, and the unique seasonal recycle between the two regions.
52 Sanlihe Rd., Xicheng District,
Beijing, China (100864)