Environmental Fluid Mechanics

, Volume 17, Issue 2, pp 323–353

Modeling and data assessment of longitudinal salinity in a low-gradient estuarine river

  • Peter Bacopoulos
  • Ethan J. Kubatko
  • Scott C. Hagen
  • Andrew T. Cox
  • Teddy Mulamba
Original Article

DOI: 10.1007/s10652-016-9486-8

Cite this article as:
Bacopoulos, P., Kubatko, E.J., Hagen, S.C. et al. Environ Fluid Mech (2017) 17: 323. doi:10.1007/s10652-016-9486-8


Continuous data of vertical-profile salinity were analyzed for four stations located successively upriver in a macrotidal estuary, the lower St. Johns River (Northeast Florida, USA). The data analysis confirmed well-mixed salinity conditions in the river with at most 1.3 ppt of vertical variability at Dames Point (river km 20), where the main variations of salinity are along the longitudinal axis of the river. Given the well-mixed salinity conditions and dominant horizontal structure of salinity variations in the river, we present and apply a barotropic, two-dimensional modeling approach for hydrodynamic-salinity transport simulation in the lower St. Johns River. When properly forced by offshore surge, high-resolution wind fields and freshwater river inflows, the model replicated the salinity measurements remarkably well, including the separation into tidal and sub-tidal components. The data and model results show that, at times, offshore winds and surge can be more influential on longitudinal salinity variations than local winds over the river. We demonstrate the importance of using proper boundary conditions to force the model relative to the minimal sensitivity of the model to parameter adjustment of horizontal mixing and uncertainty-based perturbation of wind and inflow forcings.


Salinity Hydrodynamics Estuary Macrotidal Winds Freshwater river inflow 

Funding information

Funder NameGrant NumberFunding Note
National Science Foundation
  • 1045151
NSF-Division of Mathematical Sciences
  • 0915118
Taylor Engineering, Inc./U.S. Army Corps of Engineers
  • W912EP-06-D-0012
Louisiana Sea Grant Laborde Chair Endowment
  • N/A

Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  1. 1.JacksonvilleUSA
  2. 2.Department of CivilEnvironmental and Geodetic EngineeringThe Ohio State UniversityColumbusUSA
  3. 3.Department of Civil and Environmental Engineering/Center for Computation & TechnologyLouisiana State UniversityBaton RougeUSA
  4. 4.Oceanweather Inc.Cos CobUSA
  5. 5.School of EngineeringUniversity of North FloridaJacksonvilleUSA

Personalised recommendations