Glacier projections sensitivity to temperature-index model choices and calibration strategies

Abstract The uncertainty of glacier change projections is largely influenced by models. In this study, we focus on temperature-index mass-balance (MB) models and their calibration. Using the Open Global Glacier Model (OGGM), examine influence different surface-type dependent degree-day factors, temporal climate resolutions (daily, monthly) downscaling options (temperature lapse rates, temperature precipitation corrections) for 88 glaciers with in-situ observations. Our findings indicate that higher spatial resolution observations enhance MB gradient representation due to an improved addition distinction in model also improves gradients, but lack independent limits our ability demonstrate added value increased complexity. Some choices have systematic effects, example weaker rates result smaller projected glaciers. However, often find counter balancing such as sensitivity factors snow, firn ice, which depends how accumulation area ratio changes future. Similarly, using daily versus monthly data can affect differently depending shifting balance between melt solid thresholds. study highlights importance considering minor design differences predict future volumes runoff accurately.