Articles | Volume 4, issue 2
The Cryosphere, 4, 147–160, 2010
The Cryosphere, 4, 147–160, 2010

Research article 28 Apr 2010

Research article | 28 Apr 2010

Polynyas in a dynamic-thermodynamic sea-ice model

E. Ö. Ólason and I. Harms E. Ö. Ólason and I. Harms
  • Centre for Marine and Atmospheric Research, Institute of Oceanography, University of Hamburg, Hamburg, Germany

Abstract. 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.