Trends in Snow Albedo and Radiative Forcing by Light Absorbing Particles over High Mountain Asia from Remote Sensing

High-mountain Asia (HMA) houses a substantial amount of alpine snow and ice compared to other regions globally. Due to the complex terrain and remote access throughout HMA, field measurements are sparse, expensive, and inconsistent. However, increased availability and new innovations for remote sensing products have generated a wealth of data surrounding HMA's cryosphere. With improved remote sensing techniques, numerical computer modeling, and growing collaboration, changes and trends in HMA's cryosphere are being increasingly better quantified. Despite its primary control on energy balance during melt, surface albedo of snow and ice remains an area of uncertainty within energy balance models in the region. The MODIS snow covered area and grain size (MODSCAG) and dust radiative forcing in snow (MODDRFS), which are based on spectral unmixing, have been developed to improve retrievals of surface properties over snow and ice relative to band ratio methods. Retrievals include fractional snow cover, snow grain size, and change in visible albedo due to the presence of light absorbing particles. These products can be used to retrieve broadband snow albedo and radiative forcing by light absorbing particles. We analyze the spatial and temporal trends in snow and ice albedo and radiative forcing over HMA throughout the MODIS record, and conduct a qualitative comparison with high resolution WorldView imagery. We also propose a change in the MODDRFS algorithm to better quantify radiative forcing over ice-covered terrain.