Sea ice–ocean coupling using a rescaled vertical coordinate z*

Campin, J.-M., Marshall, J. and Ferreira, D. ORCID: https://orcid.org/0000-0003-3243-9774 (2008) Sea ice–ocean coupling using a rescaled vertical coordinate z*. Ocean Modelling, 24 (1-2). pp. 1-14. ISSN 1463-5003 doi: 10.1016/j.ocemod.2008.05.005

Abstract/Summary

Realistic representation of sea ice in ocean models involves the use of a non-linear free-surface, a real freshwater flux and observance of requisite conservation laws. We show here that these properties can be achieved in practice through use of a rescaled vertical coordinate ‘‘z*” in z-coordinate models that allows one to follow undulations in the free-surface under sea ice loading. In particular, the adoption of "z*" avoids the difficult issue of vanishing levels under thick ice. Details of the implementation within MITgcm are provided. A high resolution global ocean sea ice simulation illustrates the robustness of the z* formulation and reveals a source of oceanic variability associated with sea ice dynamics and ice-loading effects. The use of the z* coordinate allows one to achieve perfect conservation of fresh water, heat and salt, as shown in extended integration of coupled ocean sea ice atmospheric model.