Regional simulation with the fully coupled physical-biogeochemical model ECOSMO II. Model details and setup specifications are described in Daewel and Schrum (2013). The basis for ECOSMO II is a baroclinic hydrodynamic coupled sea-ice model (Schrum and Backhaus, 1999), which is coupled to a lower trophic level ecosystem NPZD-model. The experiment contains hindcast simulations for the coupled North Sea and Baltic Sea ecosystem for the period 1948-2008 forced by the NCEP/NCAR reanalysis (Kalnay et al., 1996). The spatial resolution is 6’ x 10’ in the horizontal and 20 layers in the vertical. The data-set contains daily averaged data. Data for biological, physical and ice variables are stored in separate files. The 3d model grid is defined in ECOSMOII_NCEP.1948-2008.dm.griddef.000000.nc (https://cera-www.dkrz.de/WDCC/ui/cerasearch/entry?acronym=ECOSMOII_NCEP_griddef ), which contains information on vertical layer thickness in each model grid-box. The output format is netCDF.

Regional simulation with the fully coupled physical-biogeochemical model ECOSMO II. Model details and setup specifications are described in Daewel and Schrum (2013). The basis for ECOSMO II is a baroclinic hydrodynamic coupled sea-ice model (Schrum and Backhaus, 1999), which is coupled to a lower trophic level ecosystem NPZD-model. The experiment contains hindcast simulations for the coupled North Sea and Baltic Sea ecosystem for the period 1948-2008 forced by the NCEP/NCAR reanalysis (Kalnay et al., 1996). The spatial resolution is 6’ x 10’ in the horizontal and 20 layers in the vertical. The data-set contains daily averaged data. Data for biological, physical and ice variables are stored in separate files. The 3d model grid is defined in ECOSMOII_NCEP.1948-2008.dm.griddef.000000.nc (https://cera-www.dkrz.de/WDCC/ui/cerasearch/entry?acronym=ECOSMOII_NCEP_griddef ), which contains information on vertical layer thickness in each model grid-box. The output format is netCDF.

The regional reanalysis system for Continental Europe matches the domain of the CORDEX EURO-11 specifications, albeit at a higher spatial resolution, i.e., 0.055° (6 km) instead of 0.11° (12 km). It comprises the assimilation of observational data using the existing nudging scheme of COSMO complemented by snow, SST and soil moisture analysis modules and uses ERA‐Interim data as lateral boundary conditions. The reanalysis data set covers the period 1995 to August 2019. Due to the end of production of the forcing global reanalysis ERA-Interim, COSMO-REA6 has also been discontinued. A second version of COSMO-REA6, labeled "R6G2", that uses the data of the global reanalysis ERA5 as lateral boundary conditions, is currently under development at DWD.

Regional coupled ecosystem simulation of the Southern North Sea with the fully coupled Modular System for Shelves and Coasts (MOSSCO v1.0.2), an application layer of the Earth System Modeling Framework (ESMF). Here, we couple (1) the General Estuarine Transport Model (GETM) hydrodynamics and local waves with (2) the Model for Adaptive ECoSystems (MAECS) in the pelagic through the Framework for Aquatic Biogeochemical Models (FABM), and (3) the Ocean Margin Experiment Diagenesis (OMExDia) with added phosphorous cycle in the benthic through FABM. Forcing and boundary conditions are provided by (1) zero-gradient open boundary dissolved and particulate nutrients from a North Atlantic shelf simulation with the Ecosystem Model Hamburg (ECOHAM), (2) astronomical forcing of tides as boundary sea surface elevation, (3) surface winds from the CoastDat2 Climate Limited Area (CLM) hindcast, (4) sediment porosity from the North Sea Observation and Assessment of Habitats (NOAH) atlas, and (5) river fluxes and nutrient loads from the Hereon River database. The simulation covers the period 1 Feb 1960 to 31 Jan 2013, where the first year 1960 should be considered spin-up, such that analysis should be performed on complete production years 1961 to 2012. The simulation is performed on a curvilinear grid of the Southern North Sea, represented by a 98 x 139 logically rectangular grid, with varying spatial resolution of 3.7-66 sqkm per grid cell, and highest resolution in the Elbe Estuary. Vertical resolution is 20 layers in the pelagic on terrain-following sigma coordinates, and 15 z-levels resolving the ocean floor down to 20 cm. The output format is netCDF in the Climate and Forecast (CF) convention as much as possible. Complete three-dimensional data are available at 36-hour intervals. The coupled model system and the model setup are described in detail in Lemmen et al. (2018). Validations of the ecosystem coupling were performed, amongst others by Wirtz (2019, also describing the ecosystem model) and Slavik et al. (2019) using the same setup. Coupling to sediment processes is described by Nasermoaddeli et al. (2018) and to bentho-pelagic filtration by Lemmen (2018). The results specific to this long-term simulation have already been used by Xu et al. (2022). The model system and all of its components are available as free and open source and available from https://codebase.helmholtz.cloud/mossco/code.