A Global Hindcast of Ice and Ocean Conditions for 1958-2004 using ROMS

W. Paul Budgell and Vidar S. Lien
Institute of Marine Research
Bergen, Norway

A global version of ROMS coupled to a dynamic-thermodynamic ice model was used to conduct a simulation for the period 1958-2004. The horizontal grid is on a stretched spherical coordinate system providing highest resolution in the northern North Atlantic and Arctic Oceans with a grid size of 17-20 km in those regions. The model is forced with tidal potential with self attraction and earth loading corrections, so that the effects of tidal mixing and residual circulation are included. Atmospheric pressure gradient forcing helps provide more realistic exchanges across straits. The atmospheric forcing is from the CORE (Common Ocean ice Reference Experiment) data set.

Comparison with observations show good agreement in the Nordic Seas, but Gulf Stream separation is too far north in the western North Atlantic. The hindcast data set is shown to provide high quality boundary forcing fields for one-way nesting to a high resolution model of the Brents Sea region.