Numerical Models for Monitoring and Forecasting Ocean Biogeochemistry: a short description of present status

Abstract. The ability to model biogeochemical features in the ocean is a key factor in predicting the health of the ocean: it involves the representation of processes and cycles of chemical elements (such as carbon, nutrients and oxygen) and the dynamics of living organisms such as phytoplankton, zooplankton and bacteria. This paper gives an overview of the main modelling aspects aimed at describing the low trophic levels of marine ecosystems and shows how they can be coupled with advection and diffusion models to simulate the dynamics and distribution in the ocean. The complexity of biogeochemical models can vary considerably depending on the topics of interest, assumed hypothesis and simplification of the numerical parameterization. The paper also discusses the uncertainties in the numerical solution due to the lack of knowledge about the parameterizations, the initial and boundary conditions, the lack of a robust observation network and the high computational cost of running such models