Regional Arctic System Model



The Regional Arctic System Model (RASM) has been developed to advance capability in simulating critical physical processes, feedbacks and their impact on the Arctic climate system and to reduce uncertainty in its prediction. RASM is a limited-area, fully coupled ice-ocean-atmosphere-land model that uses the Community Earth System Model (CESM) framework. It includes the Weather Research and Forecasting (WRF) model, the LANL Parallel Ocean Program (POP) and Community Ice Model (CICE) and the Variable Infiltration Capacity (VIC) land hydrology model. In addition, a streamflow routing (RVIC) model was recently implemented in RASM to transport the freshwater flux from the land surface to the Arctic Ocean. Finally, marine biogeochemistry components are currently being implemented in the ocean and sea ice components to expand RASM capability into Arctic ecosystem studies. The model domain is configured at horizontal resolution of 1/12° (or ~9km) for the ice-ocean and 50 km for the atmosphere-land model components. It covers the entire Northern Hemisphere marine cryosphere, terrestrial drainage to the Arctic Ocean and its major inflow and outflow pathways, with optimal extension into the North Pacific / Atlantic to model the passage of cyclones into the Arctic. All RASM components are coupled at high frequency to realistically represent interactions among model components at inertial and longer time scales. For more information about this project, see 'Project Overview'.