Forces for recent snow cover variation on the Mount Everest region

Due to the lack of high-altitude observational datasets, a better understanding of snow cover changes and meteorological forcing for their variation in the Mount Everest region is still insufficient. This study examined changes in snow cover over the Mount Everest region and their relationship to air temperature, albedo (surface and snow), and total precipitation. This study used data from the MERRA2, ERA5-Land, JRA55, FLDAS, and CERES products spanning 41 years (1981–2021). For comparison and evaluation, we also used a ground station, Pyramid, located at a high elevation (5050 masl) at the foot of Mount Everest on the southern slope. The results confirmed a significant decline in snow cover during winter and post-monsoon seasons, which was observed in all datasets. Changes in surface and snow albedo and total precipitation positively correlate with the variation in snow cover; however, this relationship reverses with air temperature. This research suggests that atmospheric warming caused a decline in snow cover in the Mount Everest region. This decline affected snow and surface albedo, causing further warming and contributing to the continued decline in snow cover in the study area. The reduction in precipitation further contributes to the decrease in snow cover in the Mount Everest region. The variations in snow cover in this study correspond to those found in earlier studies on glacier thinning in cryosphere regions. Anthropogenic activities have linked these variations to increasing air temperatures while decreasing snowfall, precipitation, and albedo.