Simulation of melt pond evolution on first year ice

An intermediate model of melt pond evolution is presented that predicts pond size and depth changes in response to surface fluxes. The model is based on the assumption that as sea ice warms and melts, fresh water builds up in the ice pore space and eventually saturates the ice. Under these conditions, a fresh water table is defined equal to the freeboard of the ice, and ponds are produced in ice surface depressions, much like lakes in a watershed. Pond evolution is forced by applying fluxes of heat at the pond surface and a radiative transfer model for solar radiation that penetrates the pond. Results from the model using forcing data from the SHEBA experiment indicate that the model accurately simulates pond depth and fractional area over the summer melt season, with fractional area increasing linearly. Overall, ice albedo is affected primarily by the increase in pond coverage. Decrease in pond albedo from pond deepening has a much lower influence on the total albedo. Cases with predominately sunny conditions are shown to produce more rapid pond expansion than overcast cases. In both sensitivity experiments, the fractional area increases linearly.