Treatment of unresolved islands and ice in wind wave models

In ocean wave prediction models, unresolved islands are a major source of (local) errors. This paper presents a method based on a technique used in the SWAN model to deal with such islands. The method is tested in the operational global WAVEWATCH III model of the National Centers for Environmental Prediction with a one year hindcast, and the results show a local but dramatic impact on model errors. An added benefit of this methodology is the possibility to model the effects of polar ice coverage on waves continuously. A simple model to continuously model ice coverage is suggested. This new ice model shows mixed results in the tests.