Modeling Atmosphere-Ice-Ocean Mean States and Coupling in the Southern Ocean: The Impact of Model Resolution

We investigate couplings between the atmosphere, ocean, and sea ice in the Southern Ocean using the Community Climate System Model version 3.5 (CCSM3.5), and compare surface ocean processes and sea ice evolution with a high-resolution 0.1-degree (eddy-resolving) ocean and sea ice components versus the standard 1.0-degree (eddy-parameterizing) resolution. The atmosphere and land components are 0.5 degree in both cases. Results from these experiments show that increasing model resolution has a significant impact on patterns of sea ice growth and melt, as well as the evolution of properties of the surface ocean, including mixed layer depth, sea surface temperatures, and sea surface salinities. Lead and lag correlation studies suggest that these discrepancies affect ocean circulation at the gyre scale and mixing processes in the upper ocean. Spatial filtering is used to isolate relationships across scales. We will discuss the implications of modeling resolution on sea ice-ocean interactions in the Southern Ocean.