A distributed surface energy-balance model for complex topography and its application to Storglaciären, Sweden

Abstract

ABSTRACT. A grid-based surface energy-balance mass-balance model has been developed to simulate snow-and ice melt in mountainous regions with an hourly resolution. The model is applied to Storglaciären, a valley glacier in Sweden, using a 30 m resolution digital elevation model. Emphasis is directed towards computing the radiation components. These are modelled individually, considering the effects of slope angle, aspect and effective horizon. A new parameterization for snow albedo is suggested, modifying the albedo of the preceding hour as a function of time after snowfall, air temperature and cloudiness. The model is used to provide the meltwater input for discharge modelling and to assess the influence of the individual components on melt. Results are validated by means of observed melt rates, patterns of snow-line retreat and proglacial discharge. In general, simulations are in good agreement with observations. In particular, the diurnal and seasonal fluctuations of discharge are simulated remarkably well.

Reconstruction of the mass balance of Muztag Ata No. 15 glacier, eastern Pamir, and its climatic drivers

“…Sensitivity analysis of the model parameters can be used to assess uncertainties in the annual mass balance. Previous work has shown that the model output is most sensitive to parameters in parameterizations of α and turbulent heat fluxes, temperature lapse rate (T rate ), precipitation lapse rate (P rate ) and air temperature thresholds for snow (T snow ) and rain (T rain ) ( Mölg and Hardy, 2004;Hock and Holmgren, 2005;others, 2008, Reijmer andHock, 2008;Zhu and others, 2015). Both T rate and P rate on MZ15 glacier were derived from field measurements, and uncertainties in the model parameters are associated with the a snow , a firn and snow (or ice) exchange coefficient of turbulent heat flux (C S ) due to a lack of direct measurements.…”

Evaluation of a Coupled Snow and Energy Balance Model for Zhadang Glacier, Tibetan Plateau, Using Glaciological Measurements and Time-Lapse Photography

“…However, COSIMA was developed independently from the existing models. Compared to other commonly used SEB and MB approaches (e.g., Hock and Holmgren, 2005;Klok and Oerlemans, 2002;Pellicciotti et al, 2009) the parameterization of subsurface energy and mass fluxes within COSIMA is more sophisticated and directly coupled to the surface processes. COSIMA explicitly calculates meltwater percolation, the refreezing process within the snowpack under consideration of latent heat release and resulting subsurface melt, as well as the effects on subsurface temperature, snow density, and ground heat flux.…”

“…The snow line separates two glacier parts with different albedo and therefore SEB processes (Hock and Holmgren, 2005). Thus, the accurate estimation of the snow line's temporal evolution is an important factor for melt modeling, especially for the so-called "summer-accumulation type" (SAT) glaciers.…”

A DEM of the 2010 surface topography of Storglaciären, Sweden

“…be used for modelling glacier mass balance as slope and aspect are common parameters for energy balance-type models (Hock, 2005;Hock & Holmgren, 2005). Nevertheless, much of the glacier surface is relatively smooth with a mean slope of 10°(with a minimum slope of 0.5°and a maximum of 75°).…”