Can an ocean forecast model simulate the winter lead fraction in Arctic sea ice?

J. Ridley, A. Ryan and A. Sellar Met Office, Exeter, EX1 3PB UK The Forecast Ocean Assimilation Model at the UK Met Office incorporates a sea ice model and assimilates ice concentration from passive microwave observations. As part of an assessment of it's representation of the winter ice pack lead fraction, we investigate sea ice shear rupture under atmospheric forcing. The open water fraction also contributes to the rate of ice formation. It is important that an independent data set is used when assessing the model, and here it is validated against the 5km resolution GlobIce open water fraction, derived from the synthetic aperture radar observations.