Richard Barber
Ken Caldeira
Ed Laws
Ray Najjar

Scientific and technical objectives

• Develop a model of marine carbon cycling that simulates relevant characteristics of pelagic food webs and organic matter decomposition
• Incorporate that model into a global circulation model (GCM) that simulates the movement of carbon within the ocean and the exchange of CO2 between the ocean and atmosphere

Tasks

• Develop a model that describes total primary production as a function of forcing functions that can be specified in a GCM model, i.e., temperature, incident irradiance, mixed layer depth, autochthonous nutrient loading rates
• Develop a model that describes export production of organic carbon as a function of total primary production and forcing functions that can be specified in a GCM model
• Develop a model that describes export production of calcium carbonate carbon as a function of total primary production and forcing functions that can be specified in a GCM model

Hurdles/Issues

• Communication/coordination of efforts of individual PIs
• Lack of understanding of factors that regulate pelagic production of calcium carbonate
• Tendency of realistic food web models to become so complex that incorporation of them into a GCM becomes impractical
• What is minimum amount of complexity needed to capture input/output characteristics of total production model?
• What are Redfield ratios of limiting nutrients?
• How do light, temperature, and nutrient limitation interact to determine total production?

Specific Tasks

• What form should/can output from the food web models take to be useful as input to the GCM effort?
• Create a more robust set of parameterizations to include in the Ocean Carbon Model Intercomparison Project (OCMIP) simulations using output from production models below
• Develop model of total production as function of relevant forcing functions, including more than one essential nutrient;  compare predictions of model against field results from EqPac
• Develop model of export production as function of total production and relevant forcing functions; compare predictions of model against JGOFS field results
• Develop model of calcium carbonate export production as function of relevant forcing functions; compare predictions of model against field results.