DOI: 10.5281/zenodo.17723134
title: Physical and Biogeochemical Model Data for the Northern Benguela Upwelling System (1980–2020)

description: This dataset provides the monthly output fields from the coupled physical–biogeochemical modeling system developed by Salama et al. (2025). The modeling framework consists of the “Nucleus for European Modelling of the Ocean” (NEMO v4.2.2; Madec & the NEMO System Team, 2023) offline coupled to the “Biogeochemical Flux Model” (BFM v5.3; Vichi et al., 2023). The original simulation covers the larger Benguela Upwelling System (BUS) at high resolution (∼7 km), embedded within a global NEMO configuration at ∼25 km resolution and implemented through a two-way nesting strategy.

The coupled NEMO–BFM system is forced by a combination of atmospheric, oceanic, and riverine inputs. Atmospheric fluxes of momentum, heat, and freshwater are computed using the ECMWF bulk formulation forced by ERA5 reanalysis fields (Hersbach et al., 2020). Both the global and regional configurations use spatially explicit geothermal heat fluxes from Goutorbe et al. (2011). Riverine freshwater discharge is prescribed from the GloFAS reanalysis (Alfieri et al., 2013), while climatological river nutrient loads are provided by the NEWS2 model (Mayorga et al., 2010). Initial and boundary conditions for temperature and salinity are obtained from the WOA18 climatologies (Locarnini et al., 2018; Zweng et al., 2019). Open boundary conditions for biogeochemical tracers are taken from the CMCC-ESM2 historical and ssp245 simulations (Lovato et al., 2023a,b).

For the present dataset, the original model output has been spatially subsetted to the Northern Benguela Upwelling System (NBUS), extending horizontally from 7°E to 14°E and from 15.7°S to 21°S, and vertically from the surface to 1000 m depth. The dataset spans January 1980 to December 2020, providing a 41-year monthly time series of physical, biogeochemical variables in netCDF format.

The Zenodo repository contains the following compressed folders (all in .tar.gz format):

• BFM.tar.gz — Biogeochemical variables from the BFM model, including 4D fields of dissolved oxygen (O2o), gross primary production (ruPPYc), net primary production (netPPYc), and total community respiration of phytoplankton (resPPYc), bacteria (resPBAc), and zooplankton (resZOOc).

• temp_salinity.tar.gz — 4D fields of potential temperature (toce) and practical salinity (soce) from the NEMO model.

• vaisala.tar.gz — Squared Brunt–Väisälä frequency (bn2) derived from NEMO.

• MLD.tar.gz — Mixed layer depth (mldkz5) defined as the turbocline depth.

• velocity.tar.gz — Three-dimensional velocity components (uo, vo, wo) representing zonal, meridional, and vertical currents.

• volume_transport.tar.gz — Corresponding volume transports (uocetr_eff, vocetr_eff, wocetr_eff) expressed in m3 s-1.

• wind.tar.gz — Zonal and meridional ERA5 wind speed components at 10 m elevation, interpolated onto the native NEMO model grid.

• grid.tar.gz — Contains the domain grid and the mesh-mask .nc file.

The included Jupyter notebook (Oxygen.ipynb) in Oxygen_Jupyter_Notebook.tar.gz contains the full workflow used to generate the figures presented in the manuscript submitted to Journal of Geophysical Research: Oceans.

Note: *.tar.gz files here are tar-only (not gzipped). Extract with tar -xf filename.tar.gz (no gunzip / no -z).

This dataset is released under the Creative Commons Attribution 4.0 International (CC-BY 4.0) license.

List of Variables:




Symbol
Long Name
Unit


BFM.tar.gz


O2o
Dissolved Oxygen Concentration
mmol O2 m-3


ruPPYc
Gross Primary Production
mg C m-3 d-1


netPPYc
Net Primary Production
mg C m-3 d-1


resPPYc
Phytoplankton Respiration
mg C m-3 d-1


resZOOc
Zooplankton Respiration
mg C m-3 d-1


resPBAc  
Bacterial Respiration
mg C m-3 d-1


jsurO2o
Surface Air-Sea Oxygen Flux
mmol O2 m-2 d-1


temp_salinity.tar.gz


toce
Potential Temperature
°C


soce
Practical Salinity
PSU


vaisala.tar.gz


bn2
Squared Brunt–Väisälä Frequency
s-2


MLD.tar.gz


mldkz5
Mixed Layer Depth
m


velocity.tar.gz


uo
Zonal Current Velocity
 m s-1


vo
Meridional Current Velocity
m s-1


wo
Vertical Current Velocity
 m s-1


volume_transport.tar.gz


uocetr_eff
Zonal Volume Transport
m3 s-1


vocetr_eff
Meridional Volume Transport
m3 s-1


wocetr_eff
Vertical Volume Transport
m3 s-1


wind.tar.gz


u10
ERA5 Zonal Wind Speed at 10 m
m s-1


v10
ERA5 Meridional Wind Speed at 10 m
m s-1