Polynyas in a dynamic-thermodynamic sea-ice model

• Published in: The Cryosphere
• Main Authors: E. Ö. Ólason, I. Harms
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2010
• Subjects: geo; envir; Sea ice; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-4-147-2010; http://www.the-cryosphere.net/4/147/2010/tc-4-147-2010.pdf; https://doaj.org/article/430e70bbe8d347b5abb1fb0cd817befc

The representation of polynyas in viscous-plastic dynamic-thermodynamic sea-ice models is studied in a simplified test domain, in order to give recommendations about parametrisation choices. Bjornsson et al. (2001) validated their dynamic-thermodynamic model against a polynya flux model in a similar setup and we expand on that work here, testing more sea-ice rheologies and new-ice thickness formulations. The two additional rheologies tested give nearly identical results whereas the two new-ice thickness parametrisations tested give widely different results. Based on our results we argue for using the new-ice thickness parametrisation of Hibler (1979). We also implement a new parametrisation for the parameter h0 from Hibler's scheme, based on ideas from a collection depth parametrisation for flux polynya models.