The Southern Ice Ocean Model Intercomparison Project (SIOMIP).

A proposal for a southern ice ocean model intercomparison project is being developed with the impetus coming from the Antarctic sea ice community. The timing has been driven by an increase in the quantity and quality of ice thickness data from the Antarctic that can be used to verify the models. This improvement in data is set to continue with more intense field programmes during IPY and data acquired from airborne and satellite sensors. Cryospheric processes to be focussed on include ice formation in coastal polynyas, snow and snow- ice formation and the flux of ice shelf water into the ocean. It is intended that the intercomparison will be broader than sea ice and will include the needs of the southern ocean modelling community since many ice- ocean process affect the dense water masses in the Southern ocean. As well as a focus on Southern ocean water masses, the ocean model component will focus on the dynamics of the main ocean currents, their interaction with topography, and the representation of sub-grid scale processes such as down slope flows, eddy mixing and ocean convection. The ice and ocean model communities have close synergies; poor performance in one model component usually affects the performance of the other component. The aim is to include regional, circumpolar, and global ice-ocean models in different configurations, with atmospheric fluxes and stresses from the Large and Yeager data set. Discussions are currently underway with both the Southern Ocean Implementation panel and the Working group on Ocean Model Development to co-ordinate project plans. Detailed plans will be discussed with potential participants in a meeting scheduled for early 2007.