Ocean biogeochemical models are numerical tools that allow us to better understand and predict the response of the ocean system to perturbations, such as climate changes and ocean acidification. Model validation is a critical and necessary step to build confidence in model projections. This step is generally achieved through a comparison of modeled against historically observed properties, like nutrient, chlorophyll, oxygen, or total CO2 concentrations.

One issue deals with the statistical significance of this model-data comparison, in particular, where observations are scarce like in some regions of the world ocean. Another issue is which are the most suitable properties to use. For example, a perfect fit to nutrients fields may not necessary mean that the underlying physical and biogeochemical processes are represented correctly. Considering the perturbation itself, the robustness of model projections needs to be assessed. This is, for example, possible by means of model ensembles or model intercomparions (e.g. CMIP).

We invite presentations focusing on any of these aspects, or contributing in other ways to the issue of data-based evaluation of ocean biogeochemical models. The session is open to various evaluation approaches, i.e. based on multi- or single-model, ensembles, process understanding studies, regional or global as well as inverse modeling. We are particularly interested in interdisciplinary contributions combining observational work and modeling, the evaluation of biogeochemical processes, and model intercomparisons.