Realistic sea ice melt in climate models using field observations and theory

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In response to global warming, the ice covers of the Arctic and Antarctic are changing, with a significant, and accelerated, reduction in the summer extent of Arctic sea ice. The observed rapid reduction of Arctic sea ice is more extreme than the predictions of even the most pessimistic of climate models, which suggests that these models do not represent the processes controlling the reduction of sea ice adequately. Satellite observations, field work, and modelling all point to the importance of melt ponds in controlling the summer melt of Arctic sea ice but climate models do not explicitly represent melt ponds. Melt ponds form when surface snow and sea ice meltwater accumulates on the sea ice surface. Since pond-covered ice has a lower reflectivity (albedo) than bare sea ice, pond-covered ice melts up to 3 times more rapidly than bare ice. This project aims to eliminate fundamental uncertainty in the processes controlling the melt of Arctic sea ice through a combination of recently collected, closely controlled field observations and computer modelling. This project will identify the contribution of melt ponds to the rapid reduction in Arctic sea ice. A result of the research will be a new representation of sea ice melt incorporated into the CICE sea ice model, which is the sea ice model used in many climate models, including the UK Meteorological Office climate model.