Impacts of Snow-Albedo Feedback in the Tibetan Plateau, Himalayas and Central Asia

Many high elevation regions are warming at faster rates than the global mean. The response of snow cover and snow depth in these regions mainly depends on atmospheric conditions which may vary spatially and temporally. The snow pack will become thinner if increasing temperature enhances the moisture holding capacity of the atmosphere and causes an increase in liquid precipitation. On the other hand, if temperature in cold regions remains below the freezing point under a warming scenario, an increase in precipitation leads to more snow and increases the thickness of the snow pack. A decrease in snow cover causes albedo to decrease and subsequently enhances atmospheric temperature. We use global climate model simulations from the Coupled Model Intercomparison Project - Phase 5 (CMIP5) to investigate the response of snow to the projected warming over high elevation regions during this century, with a focus on the Tibetan Plateau, Himalayas and central Asia. In addition, we examine how the changes in snow may affect the atmospheric temperature through the snow-albedo feedback. Preliminary results suggest that snow extent and snow depth decrease over the study area during the 21st century, with the maximum loss in winter. The spatial pattern of changes in snow cover is more extensive than the spatial pattern of changes in snow depth. Moreover, snow depth increases over part of the western Tibetan Plateau during spring. By the end of the century, the average albedo shows a significant reduction over the high elevation region compared to lower elevations. Additionally, our results indicate that the decrease in albedo over high-elevations is primarily due to the loss of snow cover. We also examine how the snow-albedo feedback that amplifies atmospheric temperature varies among different global climate model simulations.