Downscaling Climate Simulations in the North Pacific Ocean Using a Fully Coupled Multi-Scale Model: Ecosystem Considerations

As the models used for the IPCC assessments keep evolving, interest is rising in the impacts of climate change on regional scales and their ecosystems. Because of the substantial cost of running existing climate models, critical processes often relevant to biological systems, such as mesoscale eddy induced variability and coastal upwelling are either parameterized, or simply not resolved. There are several studies using one-way downscaling of climate models to particular regions.   These studies, typically, do not permit important feedbacks in the climate system, limiting their use for future projections.  In this paper we present a fully coupled multi-scale climate model based on the NCAR-CCSM global model and the ROMS regional ocean model.  We will show that features, such as coastal upwelling, that emerge in the higher resolution component of the model, may have significant impacts on both regional and far-field climate with potential implications to ecosystem projections under climate change.