High Mountain Asia has the largest volume of glacier ice outside the polar regions and is considered the water tower of Asia. These glaciers provide drinking and irrigation water for millions of people as well as ecosystems in and beyond the mountain ranges, and are especially important in drought-affected regions. Here we circumvent the need for climate data and propose a new index entirely based on glacier surface observations from space that characterizes the accumulation type. We calculate the extent of the firn (i.e., snow that has survived at least one summer) in winter and the zone with remaining (wet) summer snow at the end of the summer using Sentinel-1 C-band Synthetic Aperture Radar (SAR) and Landsat-8 Operational Land Imager (OLI) imagery and Google Earth Engine for 22 characteristic subregions including all glaciers in High Mountain Asia for each year between 2015 and 2018.
Reference: Huang, L., Hock, R., Li, X., Bolch, T., Yang, K., Wang, N., Yao, T., Zhou, J., Dou, C., & Li, Z. (2022). Winter accumulation drives the spatial variations in glacier mass balance in High Mountain Asia. Science Bulletin, S2095927322003644. https://doi.org/10.1016/j.scib.2022.08.019