H111-0022
Improving river flow and temperature forecasts in a coupled climate, hydrology and ocean forecasting system
Friday, 11 December 2020
Poster
Alexander A Proussevitch1, Joseph Salisbury II2, Changsheng Chen3, Siqi Li3, Qichun Xu4, Tom Shyka5 and Richard B Lammers6, (1)University of New Hampshire Main Campus, Earth Systems Research Center, Durham, NH, United States, (2)University of New Hampshire, Durham, NH, United States, (3)University of Massachusetts Dartmouth, New Bedford, MA, United States, (4)University of Massachusetts Dartmouth, School for Marine Science and Technology, New Bedford, MA, United States, (5)Northeastern Regional Association of Coastal and Ocean Observing Systems, Rye, NH, United States, (6)University of New Hampshire, Earth Systems Research Center, Durham, NH, United States
Abstract:
Development and transition of the Water Balance Model (WBM) to hourly operational mode improves quality of the forecast of freshwater inflow to the coastal ocean that is being used for the Northeast Coastal Ocean Forecast System (NECOFS) supported by NOAA NERACOOS. It is coupled with a regional Weather Research and Forecasting (WRF) model for the Northeastern US and the coastal circulation model FVCOM (v.4 Finite Volume Community Ocean Model) to provide 5-day operational forecast of the Land-Atmosphere-Ocean system for the NE coastal research community and stakeholders. The transition from daily to hourly WBM operation required a significant re-formulation of land surface hydrological processes, model calibration, performance assessment, and validation of the output data and forecast quality. The transition has streamlined coupling with both key components of the NECOFS system (WRF and FVCOM models) that were originally set to hourly operations. These are now synchronized in the temporal resolutions making the process more reliable and stable, and the combined forecast product is more consistent.
In addition to harmonizing model time steps, WBM performance has been enhanced by an ongoing revision of input databases for its anthropogenic components. These primarily include hydro-infrastructure (dams) and Wastewater Treatment Plants (WWTP). The former strongly influences the timing and volume of river flow regimes and water temperature while the latter is relevant to water quality (e.g. dissolved inorganic nitrogen). Since river discharge and freshwater constituents (e.g. temperature) affect both salinity and coastal water temperature (thus water density), accurate and timely estimates are required to resolve estuarine and coastal circulation. We demonstrate that the WBM component in the NECOFS forecast system has now significantly improved predictions of freshwater flow regimes in the 5-day forecast time frame.
