Glacier melt modelling in the Donjek Range, St. Elias Mountains, Yukon Territory

摘要

Toward addressing the challenges associated with regional glacier melt modelling, I investigate the physical mechanisms of glacier melt using energy balance models, then test empirical temperature-index melt models for regional applications. First, five energy balance models are applied to two glaciers in the Donjek Range, St. Elias Mountains in order to quantify the differences between various treatments of the glacier surface temperature and subsurface heat flux. A model that assumes a constant 0°C surface temperature overestimates cumulative melt by 9--13%, but a simple model that computes surface temperatures from the residual of the energy balance yields significant improvement. Second, I evaluate the transferability of spatially-distributed temperature-index melt models through the application of calibrated model parameters to periods and locations that differ from those used for calibration. Results show that the calibrated model parameters can be transferred between the study glaciers with minimal reductions in skill.;Keywords. temperature-index modelling; energy balance; surface temperature; St. Elias Mountains; glacier mass-balance; regional modelling.