During the ODEON project, beyond-state-of-the-art modelling tools were developed, able to simulate the atmospheric Fe-cycle in an ESM, taking also into account the past, present-day and the projected socioeconomic impacts in our calculations. For this, the European state-of-the-art Earth System Model (ESM) EC-Earth was here extended with a detailed atmospheric Fe cycle: the atmospheric Fe deposition fields from the atmospheric chemistry transport model of the EC-Earth were coupled to its ocean biogeochemistry model, by replacing its simplistic Fe input configuration (which was based only on the atmospheric mineral dust deposition). In our calculations, we considered the up-to-date understanding of the effects of air quality on the atmospheric Fe-cycle in order to investigate the ocean biogeochemistry perturbations. The scientifically high risk/high gain element of the proposal was, however, the incorporation of an on-line Fe-scheme in the atmosphere and couple it in the ocean. For this, each module was carefully evaluated after each phase of model development, and present-day simulations were thoroughly compared to observations. Each successful evaluation of the project was an intermediate target (milestone) that allowed moving to the next phase of the project. Thus, the couplings of air-quality and atmospheric Fe input to the oceanic biogeochemistry was activated in a stepwise approach via Uncoupled (U) and Coupled (C) configurations of the Fe input. For the U-runs, a Fe- containing aerosol atmospheric processing scheme was developed and it implemented, for the first time, in the atmospheric chemistry transport model of EC-Earth. For the C-runs, the ocean biogeochemistry model’s current Fe input parameterization into the ocean was replaced by the new ODEON’s Fe deposition fields. Note that the U-runs provided us reference for C-runs’ evaluations of Fe deposition fluxes as well as for the novel estimation of the marine primary productivity, i.e. under historical (i.e. preindustrial-to-present) and future changes.
ODEON’s results and code developments were disseminated to the scientific-groups and science-users of the EC-Earth consortium, who will benefit mainly from its innovated methodology of potential air-quality impacts on marine primary production. In more details, the project provided a new code for calculating the atmospheric chemistry in EC-Earth, as well as a set of atmospheric concentrations and deposition fields for carbon-cycle simulations, improving overall the knowledge chain and delivering reliable Earth system change information to policy/decision makers. Note that all project’s results are open-access available, with no IPR protection issues and links to all publication and are available online via the social networks and through digital repositories.