Date of Award
2026
Degree Type
Thesis
Degree Name
Master of Science in Oceanography
Specialization
Physical Oceanography
Department
Oceanography
First Advisor
Christopher Kincaid
Abstract
The Ocean State Ocean Model (OSOM), funded and developed through the National Science Foundation’s (NSF) Established Program to Stimulate Competitive Research (EPSCoR), was designed to simulate the physical dynamics of Rhode Island’s estuaries and shelf waters. However, the model struggled to capture key features of summer circulation in Rhode Island Sound (RIS), most notably the westward flowing coastal current and vertical stratification profile found in May through September. Significant errors in modeled lateral and vertical density gradients indicated that the thermohaline structure, physical mixing parameters, and forcing inputs required comprehensive revision. Using historical datasets from the National Oceanic and Atmospheric Administration (NOAA), as well as research cruises of RIS in 2010 and 2011, OSOM’s input framework was rewritten and recompiled. Surface forcing fields were replaced with higher resolution, spatially varying 2010 products from the European Centre for Medium Range Weather Forecasts Reanalysis Version 5 (ERA5) and the North American Mesoscale Forecast System (NAM). Initial and boundary condition files were rebuilt to include realistic vertical structure to enhance stratification and correctly capture density gradients. An extensive suite of model simulations was conducted to test combinations of four turbulent mixing schemes, three advection schemes, and four mixing parameter configurations in order to evaluate their influence on the baroclinic structure and residual circulation of RIS within OSOM. The best performing configurations included the k-omega turbulent mixing scheme with Kantha-Clayson and Horizontal buoyancy frequency (N2) and stratification (S2) averaging, as well as the third-order upstream horizontal advection and fourth order centered vertical advection schemes for tracers, which led to improvements in modeled temperature, salinity, and velocity fields. This OSOM code successfully reproduced the observed coastal current direction and magnitude within 20% error across the 2010 stratified season. With these improved physics, the model correctly tracked water parcel movement from Buzzard’s Bay and central RIS toward Narragansett Bay (NB), revealing potentially relevant pathways to nitrogen loading and larval transport. This study highlights the importance of rigorous model tuning and the role of realistic inputs to capture complex seasonal dynamics in coastal regimes on fine temporal scales.
Recommended Citation
Fruhwirth, Ainsley, "DATA IMPROVED MODELS APPLIED TO ESSENTIAL OCEANOGRAPHIC PROCESSES IN RHODE ISLAND COASTAL WATERS" (2026). Open Access Master's Theses. Paper 2733.
https://digitalcommons.uri.edu/theses/2733