Nesting Resolution Study of Narragansett Bay Using the Regional Ocean Modeling System

Xiaoyu Fan, Brown University, Department of Earth, Environmental and Planetary Sciences, Providence, RI, United States, Haili Wang, Nanjing University of Information Science and Technology, Nanjing, China, Baylor Fox-Kemper, Brown University, Earth, Environmental and Planetary Sciences, Providence, RI, United States and Changming Dong, University of California, Department of Atmospheric and Oceanic Sciences, Los Angeles, United States
Narragansett Bay is located at the southern end of Rhode Island and Massachusetts, which is a complex semi-closed tidal estuary including the major Providence River, Blackstone River, Pawtuxet River and Taunton River freshwater inputs. The Regional Ocean Modeling System (ROMS) is a hydrostatic ocean model which is widely used in ocean simulation and prediction with the kernel of physics, biogeochemical, sediment and sea ice. The purpose of this study is to evaluate the performance of ROMS in the simulation of Narragansett Bay, in order to build the capability of forecasting the local marine conditions and water quality relevant to marine life protection and pollution. Previous studies have illustrated that ROMS is useful in coastal modeling with a grid resolution of 100m and larger. One instance of this model is the Ocean State Ocean Model (OSOM) which is being developed by URI and Brown. This study compares the performance of the OSOM Rutgers ROMS variant in items of temperature, salinity, density, and velocity versus nested subdomains of higher and very high resolution in the Providence River at 4-meter horizontal resolution. The different resolution modes are validated against observational data from buoys and CTD casts during the same period, July 2006. Correlation coefficient, average, mean square deviation are used to rank the different resolution cases. The next stage in this study is to compare these results against nonhydrostatic versions of ROMS at the same resolution.