Measurement and simulation of snow and superimposed ice at the Kongsvegen glacier, Svalbard (Spitzbergen)

摘要: [1] Multiyear glaciometeorological data have been collected at about the equilibrium line of Kongsvegen glacier in Svalbard. During first summer investigation period, 0.6 m superimposed ice (SI) was built up because effective meltwater refreeze upon former surface. Thus winter accumulation is completely retained from runoff, and latent heat released equivalent to 27% July net radiation. This layer, as well part year's ice, disappeared during subsequent summer. Using a physically based snow model, evolution pack properties observed amount SI successfully reproduced. However, latter only possible by modifying model's water transport routine also treat effects ponding water, which observed. Two distinct phases formation can be distinguished. A one (15 cm) initiated soon has penetrated underlying cold ice. Toward end melt however, remaining body rapidly formed intense atmospheric cooling. The availability plays an essential role this context. following initial refreezing phase terminated exposure newly whole actual year major melted then. positive ice-albedo feedback process additional there. Sensitivity studies prove that model results their interpretation do not critically depend on uncertainties input parameters. Despite local nature these are valuable steps toward understanding regional distribution Arctic glaciers climate sensitivity. Remote sensing indicate presently covers 35% Kongsvegen's surface area.