Dataset: Numerical experiments on the sensitivity of Chesapeake Bay N2O cycles to climate warming and nutrient reductions and the associated code and input files

A three-dimensional numerical model of the Chesapeake Bay (East Coast of the United States) was used to simulate the N2O cycle. The model is an implementation of the Regional Ocean Modeling System (ROMS, https://www.myroms.org/) with modules for sediment resuspension (Warner et al. 2008) and biogeochemistry (St-Laurent et al. 2020), with the latest addition of N2O as a separate state variable. It simulates hydrodynamics and biogeochemistry with a horizontal resolution of approximately 1.8 km and 20 topography-following vertical levels. Physical forcings include the ERA5 reanalysis (3-hourly) and tidal constituents from Szpilka et al. (2016). The dataset includes four primary numerical experiments designed to highlight the sensitivity of the Chesapeake Bay N2O cycle to climate warming and terrestrial nutrient management. The reference run was conducted for the year 2016, which represents a normal streamflow year. Three sensitivity experiments retained the same model forcings as in the reference run, except for one of the following combinations: Decreased atmospheric N2O concentrations, decreased atmospheric temperature, and increased riverine nitrate and organic nitrogen concentrations to 1986 levels (Test1986). Decreased atmospheric N2O concentrations and increased riverine nitrate and organic nitrogen concentrations to 1986 levels (Test1986warming). Increased atmospheric N2O concentrations, increased atmospheric temperature, and decreased riverine nitrate and organic nitrogen concentrations to 2050 levels (Test2050). The file Results_for_plot.zip includes model outputs used to generate figures, including monthly Bay-wide N2O distribution and the daily N2O budget integrated over the Bay. In addition to the model outputs, this archive contains the computer code (ROMS_Code.zip) and the input files necessary to reproduce the model results (input_files.zip). The total size of the dataset is approximately 5 GB. References: Scavia, D., Kelly, E. L. A., & Hagy, J. D. (2006). A simple model for forecasting the effects of nitrogen loads on Chesapeake Bay hypoxia. Estuaries and Coasts, 29(4), 674–684. https://doi.org/10.1007/bf02784292 St-Laurent, P., Friedrichs, M. A. M., Najjar, R. G., Shadwick, E. H., Tian, H., & Yao, Y. (2020). Relative impacts of global changes and regional watershed changes on the inorganic carbon balance of the Chesapeake Bay. Biogeosciences, 17(14), 3779–3796. https://doi.org/10.5194/bg-17-3779-2020 Warner, J. C., Sherwood, C. R., Signell, R. P., Harris, C. K., & Arango, H. G. (2008). Development of a three-dimensional, regional, coupled wave, current, and sediment-transport model. Computers & Geosciences, 34(10), 1284–1306. https://doi.org/10.1016/j.cageo.2008.02.012