The surface energy balance and its importance for superimposed ice formation (SEBISUP)

Measurements of snow metamorphism and superimposed ice formation and the associatedmeteorological boundary conditions are presented. The observations were performed duringmelt onset, between May 20 and June 03, 2002, on first-year fast ice in Kongsfjorden,Svalbard. During the observation period, meteorological conditions changed from typical late-winterto summer conditions. This transition was characterized by a major change in the long-waveradiation fluxes, and associated air and snow temperature increases. Consequently,extensive snow melt was observed and the transformation of snow into superimposed ice. The0.23 m thick snow cover completely disappeared within 5 days, and was transformed into 5 to6 cm of superimposed ice, covered by a thin layer of deteriorated ice.