Abstract: The degree-day model, a widely used approach for ice- and snow-melt computation, rests upon a relationship between snow or ice melt and air temperature that is usually expressed in the form of positive temperature. The degree-day factor (DDF) is an important parameter for the model, and its spatial variation largely affects the accuracy of snow- and ice-melt simulations. Across High Mountain Asia (HMA), only a few glaciers have long-term observational records over the past decades, failing to provide necessary parameters for regional melting simulation based on degree-day models. In this study, we collected investigations and observations on 40 glaciers located in different regions of HMA, and estimated the transfer functions for snow and ice DDFs to obtain the dataset of spatial distributions of DDFs for snow and ice in HMA. These data, with a spatial resolution of 0.5°, were stored in GeoTIFF format in 32-bit floating point. Their accuracy is confirmed through a comparison between regional mass balance simulations using this dataset and observations in a typical region. The dataset provides model parameters for the study of regional glacier melting process and its impact on water resources and associated glacier disasters in HMA. It also provides data support for further analysis of glacier change and climate change, water resources change and its disaster effects in HMA.
Keywords: glacier melt; degree-day factor; degree-day model; water resources; High Mountain Asia