Toward improved forecasts of sea-ice thickness

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It is well known that the ice extent in the Arctic has been decreasing in recent years. It is much less well known how the thickness of the ice in the Arctic is changing. This is because sea ice thickness is more difficult to measure than sea ice extent from satellites. Sea ice thickness can be estimated using data from a satellite sensor that measures radiation in the infrared band. Because satellite observations contain some error, they should be combined with other sources of information when possible. In this research we will generate sea ice thickness forecasts by combining the information from the satellite sensor with that from a numerical model. The accuracy of the forecasts will be verified by comparing the results with independent observations. It is of particular interest to be able to generate forecasts of sea ice thickness that can be given to ships, to ensure safe navigation in ice-infested waters. Results from the research will be communicated to the Canadian Ice Service such that they can be applied to real problems in a timely manner.A great deal of emphasis has been placed on the role of the so called 'ice-albedo feedback mechanism' in decreasing sea ice extent in the Arctic. This is the mechanism by which melting ice allows for more open water to be exposed, and because the open water is darker than the ice it can absorb more of the heat from the sun, allowing more ice to melt. However, work has only begun on understanding the role the heat stored below the surface layer in the ocean may play on the sea ice. This is particularly difficult because the size of the eddies which transfer heat in the ocean decreases with increasing latitude, so fine numerical meshes are required to capture the eddies in the Arctic. Here we will investigate a parameterization for the eddies, called the NS-alpha model, on the circulation and eddies in the Arctic ocean. If successful, the parameterization can be used for climate simulations as part of the suite used by the Intergovernmental Panel on Climate Change.