DALROMS-NWA12 v1.0 is a coupled circulation-sea ice-biogeochemistry modelling system based on ROMS, CICE, and MCT. The model domain covers the North Atlantic Ocean from ~81 deg W to ~39 deg W and ~33.5 deg N to 76 deg N. This record includes the files necessary for nudging the simulated temperature and salinity towards Copernicus GLORYS12V1 reanalysis values in a simulation from 1 September to 31 December 2013. The remaining input files for this period are available at https://doi.org/10.5281/zenodo.12752190 and https://doi.org/10.5281/zenodo.12735153. Model codes, scripts for compiling the model, and sample CPP header files and runtime parameter files (namelists) for phyiscs-only simulations are available at https://doi.org/10.5281/zenodo.12752091. CPP header and runtime parameter files for the biogeochemistry module are available upon request. Sample output files (from the physics and biogeochemistry modules) are available at https://doi.org/10.5281/zenodo.12744506 and https://doi.org/10.5281/zenodo.12746262.