The subpolar open seas are under scrutiny for the role they may play in the global carbon dioxide (CO2) cycle. While the level of biological production and the fate of that production are central issues in the inquiry, the mechanisms controlling even the level of biological production in the subpolar open seas are not understood. This project will reformulate an ecosystem process model integrating a biological model of lower trophic level interactions, including phytoplankton production, grazing, and nutrient regeneration, into a one-dimensional physical model of the upper ocean. The model will be developed and first tested against the extensive physical and biological observations from Ocean Station P (50 Degrees N 145 Degrees W) in the open subarctic Pacific Ocean. Effects of physical-biological interactions and trophic complexity will be assessed. The model will then be applied to the other two subpolar open seas, the subarctic Atlantic and the subantarctic circumpolar ocean which, because of biological and physical processes favorable to removal of CO2 from the surface layer and its sequestration in the deep ocean, are thought to play a major role in the global CO2 cycle.
