Reconstruction of Glacier Mass Balance with Surface Energy Balance Modeling across Southwestern Canada

Current state-of-the-art glacier models for regional and global scales mostly rely on empirical models, such as temperature-index models, which require glacier-specific calibration with in-situ mass balance measurements. In the absence of these measurements, the models suffer from large uncertainties in their projections of glacier mass changes, especially at local scales. One way to address this issue is to transition from the empirical models toward more physics-based models, such as surface energy balance (SEB) models of glacier melt. In this study, we evaluate the performance of a glacier evolution model based on a SEB model with minimal calibration for nearly 15,000 glaciers in Southwestern Canada for the period of 1979–2021. The SEB model is forced with ERA5 reanalysis data with minimal bias corrections or statistical downscaling. The empirical models for accumulation and albedo are, however, calibrated to maximize the match between simulated and observed glaciological mass balance availabe for about 20 glaciers in this region. The simulated regional mass balance and area change are then evaluated against the geodetic mass balance as observed for all glaciers in the region over the last two decades. This study contributes to a better understanding of the applicability of SEB models with minimal calibration in regional glaciation modeling in order to narrow uncertainties in glacier melt projections.