The ECCO-Darwin Data-assimilative Global-ocean Biogeochemistry Model: A New Modeling Framework for Ocean Carbon Cycle and Ecosystem Studies

Abstract:

The Estimating the Circulation and Climate of the Ocean (ECCO) consortium uses state-of-the-art ocean circulation models and global observations to make the best possible estimates of ocean circulation and its role in climate. Here we present ECCO-Darwin, which combines ECCO state estimates with the Darwin Project ecosystem model to provide a new global-ocean biogeochemistry state estimate from 1992–near-present. ECCO-Darwin represents an important technological step forward as it is the first global-ocean biogeochemistry model that (1) ingests both physical and biogeochemical observations into the model in a property-conserving manner and (2) considers how the nature of the ocean carbon sink and marine ecosystems have changed over multiple decades. For carbon-related studies, ECCO-Darwin produces surface-ocean pCO₂ and air-sea CO₂ fluxes that exhibit broad-scale consistency with interpolation-based products, particularly in the subtropical and equatorial regions. Additionally, compared to the Global Carbon Project (GCP) models, ECCO-Darwin has a global carbon sink and interannual variability that is more consistent with interpolation-based products. We also provide examples of downscaling the global-ocean ECCO-Darwin model for regional and coastal applications, which allows end users to generate high-resolution biogeochemical simulations for their region of interest. As the ECCO ocean circulation estimates become more accurate and lengthen in time, ECCO-Darwin will become an ever more accurate tool for identifying and predicting the consequences of natural and anthropogenic perturbations to the open- and coastal-ocean carbon cycle and the climate-related sensitivity of marine ecosystems.