Modeling Seasonal to Decadal Variability in Global Ocean Carbon

A 3D ocean model is used to estimate seasonal, interannual and decadal variability of carbon in the global oceans. The model, called the NASA Ocean Biogeochemical Model (NOBM) contains an explicit prognostic ecosystem model, that is coupled with a carbon model, including dissolved organic carbon, dissolved inorganic carbon, and pCO2. We track the variability of carbon and ecosystem components from 1997 through 2005. This period includes several major and minor ENSO events. Seasonal variability of ecosystem and carbon components is pronounced, as is interannual variability of ecosystem and particularly primary production. Interannual carbon variability is less pronounced. Assimilation of satellite ocean chlorophyll into the model provides substantially improved representation of simulated chlorophyll, but carbon components are less affected. A multi-variate approach to nutrient further improves them, but again changes in carbon components are modest. Statistical comparisons with in situ and satellite data are encouraging.