Comparison of the Princeton Ocean Model and the Regional Ocean Modeling System Hindcasts in the Delaware River and Bay

The National Oceanic and Atmospheric Administration is in the process of developing a nowcast/forecast system for Delaware River and Bay. The Delaware Bay Operational Forecast System (DBOFS) will extend from the head of tide at Trenton, NJ through the Bay entrance out onto the continental shelf and will supplement the Delaware Bay Physical Oceanographic Real Time System (PORTS), which was installed in 2003 to provide observed, real-time water surface elevation, currents, temperature, salinity, and meteorological information. In conjunction with the DBOFS development effort, the Princeton Ocean Model (POM) and the Regional Ocean Modeling System (ROMS) have been applied with a common medium resolution grid in hindcast mode using common forcings to simulate two 15-day periods in March (high river flow) and September (low river flow) 1984. Herein, we compare and contrast the hindcast simulation results versus the National Ocean Service Delaware River and Bay 1984 Circulation Survey measurements of water surface elevation, currents, salinity, and temperature. The effects of a spatially varying bottom friction, subtidal water level forcings at the Chesapeake and Delaware Canal boundary, navigation channel bathymetry, and upriver storage areas on water level, current, and salinity response are considered. In conclusion, plans for further DBOFS development with ROMS using a finer resolution grid are presented.