Application of an improved surface energy balance model to two large valley glaciers in the St. Elias Mountains, Yukon

• Published in: Journal of Glaciology
• Main Authors: Tim Hill, Christine F. Dow, Eleanor A. Bash, Luke Copland
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2021
• Subjects: Energy balance; melt surface; surface mass budget; Environmental sciences; GE1-350; Meteorology. Climatology; QC851-999; Yukon; Canada; Kaskawulsh Glacier; Lowell Glacier; glacier*; Journal of Glaciology
• Online Access: https://doi.org/10.1017/jog.2020.106; https://doaj.org/article/ca1c11a0bcfe4a6ba015069a68b4e0e1

Glacier surficial melt rates are commonly modelled using surface energy balance (SEB) models, with outputs applied to extend point-based mass-balance measurements to regional scales, assess water resource availability, examine supraglacial hydrology and to investigate the relationship between surface melt and ice dynamics. We present an improved SEB model that addresses the primary limitations of existing models by: (1) deriving high-resolution (30 m) surface albedo from Landsat 8 imagery, (2) calculating shadows cast onto the glacier surface by high-relief topography to model incident shortwave radiation, (3) developing an algorithm to map debris sufficiently thick to insulate the glacier surface and (4) presenting a formulation of the SEB model coupled to a subsurface heat conduction model. We drive the model with 6 years of in situ meteorological data from Kaskawulsh Glacier and Nàłùdäy (Lowell) Glacier in the St. Elias Mountains, Yukon, Canada, and validate outputs against in situ measurements. Modelled seasonal melt agrees with observations within 9% across a range of elevations on both glaciers in years with high-quality in situ observations. We recommend applying the model to investigate the impacts of surface melt for individual glaciers when sufficient input data are available.