ECOSMO II(CHL): a marine biogeochemical model for the North Atlantic and the Arctic

TitleECOSMO II(CHL): a marine biogeochemical model for the North Atlantic and the Arctic
Publication TypeJournal Article
Year of Publication2022
AuthorsYumruktepe, C, Samuelsen, A, Daewel, U
JournalGeoscientific Model Development
PublisherCopernicus GmbH

ECOSMO II is a fully coupled bio-physical model of 3D hydrodynamics with an intermediate-complexity NPZD (nutrient, phytoplankton, zooplankton, detritus) type biology including sediment-water column exchange pro- cesses originally formulated for the North Sea and Baltic Sea. Here we present an updated version of the model in- corporating chlorophyll a as a prognostic state variable: ECOSMO II(CHL). The version presented here is online coupled to the HYCOM ocean model. The model is intended to be used for regional configurations for the North Atlantic and the Arctic incorporating coarse to high spatial resolu- tions for hind-casting and operational purposes. We provide the full descriptions of the changes in ECOSMO II(CHL) from ECOSMO II and provide the evaluation for the inor- ganic nutrients and chlorophyll a variables, present the mod- elled biogeochemistry of the Nordic Seas and the Arctic, and experiment on various parameterization sets as use cases targeting chlorophyll a dynamics. We document the perfor- mance of each parameter set objectively analysing the ex- periments against in situ, satellite and climatology data. The model evaluations for each experiment demonstrated that the simulations are consistent with the large-scale climatological nutrient setting and are capable of representing regional and seasonal changes. Explicitly resolving chlorophyll a allows for more dynamic seasonal and vertical variations in phyto- plankton biomass to chlorophyll a ratio and improves model chlorophyll a performance near the surface. Through experi- menting with the model performance, we document the gen- eral biogeochemisty of the Nordic Seas and the Arctic. The Norwegian and Barents seas primary production show dis- tinct seasonal patterns with a pronounced spring bloom dom- inated by diatoms and low biomass during winter months. The Norwegian Sea annual primary production is around double that of the Barents Sea while also having an earlier spring bloom.

Refereed DesignationRefereed
Author Address