ChesROMS-ECB (Chesapeake Regional Ocean Modeling System – Estuarine Carbon Biogeochemistry) is an open-source Chesapeake Bay implementation of the Regional Ocean Modeling System (ROMS). The original model domain (Feng et al., 2015) includes the bay and a portion of the continental shelf (Fig. 1) with a curvilinear horizontal discretization (~1.8 km) and 20 topography-following levels in the vertical (Xu et al., 2012). A newer implementation of ChesROMS-ECB uses a higher resolution grid (~600 m) that includes the eastern shore of Virginia and Maryland, as well as optional tributary nesting (~150 m) and wetting and drying along the coastline.
The ROMS physical kernel is coupled to a biogeochemical module (Estuarine Carbon Biogeochemistry, ECB) at every baroclinic time step (60 s) using a positive-definite advection scheme. The ECB module represents the nitrogen and carbon cycles of the lower trophic level planktonic ecosystem with additional processes specific to estuarine systems (see equations in supplementary information of St-Laurent et al., 2020). ECB’s multiple state variables include: nitrate, ammonium, oxygen, inorganic suspended solids, dissolved inorganic carbon, total alkalinity, phytoplankton, zooplankton, small and large nitrogen and carbon detritus, and separate semilabile and refractory dissolved organic carbon and nitrogen components. Terrestrial inputs are typically derived from watershed models such as the Chesapeake Bay Program’s Phase 6 model (Shenk and Linker et al., 2013) or the Dynamic Land Ecosystem Model (Tian et al., 2015; Yang et al., 2015), and atmospheric forcing is from the ECMWF Reanalysis v5.
The ChesROMS-ECB modeling system was developed by Dr. Marjy Friedrichs and colleagues at the Virginia Institute of Marine Science, and builds upon the original open source ChesROMS physical model developed at the University of Maryland Center for Environmental Science. This modeling system, which is available upon request from Dr. Friedrichs and Dr. St. Laurent, has been used in a wide variety of Chesapeake Bay studies. These include examinations of: the impacts of both climate change (Irby et al., 2018) and atmospheric nitrogen deposition (Da et al., 2018) on hypoxia; confidence in the impact of regulatory nutrient reduction on Chesapeake Bay water quality (Irby and Friedrichs, 2019); the effects of water clarity on estuarine temperature (Kim et al., 2020); the impact of sediment processes on estuarine biogeochemistry (Moriarty et al., 2020) and the relative impacts of global and regional watershed changes on the inorganic carbon balance of the Chesapeake Bay (St-Laurent et al., 2020; see Featured Modeler below). ChesROMS-ECB has also been used to quantify future shifts in sandbar shark (Crear et al., 2020a) and cobia (Crear et al., 2020b) habitat due to climate change, and annually is used to generate the VIMS Chesapeake Bay Dead Zone Report Hypoxia Dead Zone Report.
References:
Crear, D.P., R.J. Latour, M.A.M. Friedrichs, P. St-Laurent, K.C. Weng, 2020a. Climate sensitivity of a shark nursery habitat. Marine Ecology Progress Series, 652, 123-136, doi.org/10.3354.meps13843.
Crear, D.P., B.E. Watkins, M.A.M. Friedrichs, P. St-Laurent, K.C. Weng, 2020b. Estimating shifts in phenology and habitat use of cobia in Chesapeake Bay under climate change. Frontiers in Marine Science, 7:579135. doi.org/10.3389/fmars.2020.579135.
Feng, Y., M. A. M. Friedrichs, J. Wilkin, H. Tian, Q. Yang, E. E. Hofmann, J. D. Wiggert, R. R. Hood, 2015. Chesapeake Bay nitrogen fluxes derived from a land-estuarine ocean biogeochemical modeling system: Model description, evaluation, and nitrogen budgets, J. Geophys. Res. Biogeosci., 120, 1666-1695, doi.org/10.1002/2015JG002931.
Irby, I.D., M.A.M. Friedrichs, F. Da, K. Hinson, 2018. The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay. Biogeosciences, 15, 2649-2668, doi.org/10.5194/bg-15-2649-2018
Irby, I.D.,M.A.M. Friedrichs, Estuaries and Coasts, 2019. Evaluating confidence in the impact of regulatory nutrient reduction on Chesapeake Bay water quality. Estuaries and Coasts, 42, 16-32. doi.org/10.1007/s12237-018-0440-5.
Kim, G.E., P. St-Laurent, M.A.M. Friedrichs, A. Mannino, 2020. Impacts of water clarity variability on temperature and biogeochemistry in the Chesapeake Bay. Estuaries & Coasts, doi.org/10.1007/s12237-020-00760-x.
Moriarty, J.M., M.A.M. Friedrichs, C.K. Harris, 2020. Seabed resuspension in the Chesapeake Bay: Implications for biogeochemical cycling and hypoxia. Estuaries & Coasts, doi.org/10.1007/s12237-020-00763-8
Shenk, G.W., Linker, L.C., 2013. Development and application of the 2010 Chesapeake Bay Watershed total maximum daily load model. J. Am. Water Resour. Assoc. 49, 1042–1056. https://doi.org/10.1111/jawr.12109
St-Laurent, P., M.A.M. Friedrichs, R.G. Najjar, E.H. Shadwick, H. Tian, Y. Yao. Relative impacts of global changes and regional watershed changes on the inorganic carbon balance of the Chesapeake Bay, 2020, Biogeosciences, 17, 3779–3796, doi.org/10.5194/bg-17-3779-2020
Tian, H., Q. Yang, R. Najjar, W. Ren, M.A.M. Friedrichs, C.S. Hopkinson, S. Pan, 2015. Anthropogenic and climatic influences on carbon fluxes from eastern North America to the Atlantic Ocean: A process-based modeling study. J. Geophys. Res. Biogeosci., 120, 757-772, doi.org/10.1002/2014JG002763.
Xu, J., W. Long, J. D. Wiggert, W. J. Lanerolle, C. W. Brown, R. Murtugudde, R. R. Hood (2012) Climate forcing and salinity variability in the Chesapeake Bay, USA. Estuaries and Coasts, 35: 237-261, doi.org/10.1007/s12237-011-9423-5.
Yang, Q., H. Tian, M.A.M. Friedrichs, C. Hopkinson, C. Lu, 2015. Increased nitrogen export from eastern North America to the Atlantic Ocean due to climatic and anthropogenic changes during 1901-2008. J. Geophys. Res. Biogeosci, 120, 1046-1068, doi.org/10.1002/2014JG002763.