Intercomparison of Arctic sea ice simulation in ROMS-CICE and ROMS-Budgell

Abstract

Accurate representation of the complex ocean-sea ice interaction is still an ongoing effort. In this study, we have coupled the Community Ice Code (CICE) model and Regional Ocean Modeling System (ROMS) to develop a high-resolution regional coupled ocean-sea ice model for polar regions. This setup allows us to investigate the interaction between ocean and sea ice in detail. The Coupled-Ocean-Atmosphere-Wave-Sediment-Transport (COAWST) modeling system is the core of this coupled model. Currently, the ROMS model in COAWST uses the Budgell sea ice model, embedded as a sub-module in it but introducing a more comprehensive sea ice model (CICE) may provide a better treatment of sea ice. Here, we present our preliminary results based on the coupled ROMS-CICE and ROMS-Budgell simulation over the Arctic Ocean. Our results show that both CICE and Budgell models perform better in simulating sea ice concentration during winter than during summer. Compared to the satellite observations, sea ice concentrations from the CICE model in most subregions have higher correlations and smaller centered root mean square errors, showing higher simulation skills. The sea ice thickness biases are larger in the Budgell model in the early months of the year, whereas in the CICE model they are larger after October. Both CICE and Budgell models overestimate the sea ice extent and sea ice volume in summer, and their performances differ in the subregions.