A Numerical Tool for Dissolved Oxygen Simulation in the Western Mississippi Sound

Abstract

Bazgirkhoob, H.; Linhoss, A., and Armandei, M., 2022. A numerical tool for dissolved oxygen simulation in the western Mississippi Sound. Journal of Coastal Research, 38(4), 699–711. Coconut Creek (Florida), ISSN 0749-0208. Dissolved oxygen is an indicator of aquatic health. Hydrodynamic–water quality models facilitate the understanding of flow dynamics and dissolved oxygen in estuarine systems. In this study, dissolved oxygen concentration, seasonality, and vertical stratification were studied in the western Mississippi Sound, Northern Gulf of Mexico. Visual Environmental Fluid Dynamic Code and the water quality model CE-QUAL-ICM were linked together to develop a three-dimensional hydrodynamic and water quality model of the western Mississippi Sound. The model was verified and validated for nutrients and chlorophyl a. Then, the modeled results for dissolved oxygen were compared to measured data. Mean observed dissolved oxygen ranged between 6.29 and 8.48 mg/L in the top and bottom layers at each site. The root mean squared error between measured and modeled dissolved oxygen ranged between 1.30 and 2.87 mg/L. Results indicate that the model was able to capture measured seasonal trends and vertical stratification. The model simulated more realistic results in shallower areas compared to deeper areas. Overall, the model simulated slightly higher dissolved oxygen than what was measured, although 27% of the stations showed no statistical difference between the modeled and measured dissolved oxygen. These results are useful for interpreting the value of this model for future ecological studies. The model can be used as a tool to provide better understanding of the dissolved oxygen dynamics due to multiple scenarios such as hurricanes and storms.