Articles | Volume 4, issue 4
Ocean Sci., 4, 239–246, 2008
https://doi.org/10.5194/os-4-239-2008
Ocean Sci., 4, 239–246, 2008
https://doi.org/10.5194/os-4-239-2008

  19 Nov 2008

19 Nov 2008

Improving the parameterisation of horizontal density gradient in one-dimensional water column models for estuarine circulation

S. Blaise1 and E. Deleersnijder2 S. Blaise and E. Deleersnijder
  • 1Université catholique de Louvain, Unité de Génie Civil et Environnemental, Louvain-la-Neuve, Belgium
  • 2Université catholique de Louvain, Centre for Systems Engineering and Applied Mechanics, Louvain-la-Neuve, Belgium

Abstract. A new parameterisation of horizontal density gradient for a one-dimensional water column estuarine model, inspired by the first-order finite-difference upwind scheme, is presented. This parameterisation prevents stratification from growing indefinitely, a deficiency usually referred to as "runaway stratification". It is seen that, using this upwind-like parameterisation, the salinity must remain comprised between upper and lower bounds set a priori and that any initial over- or under-shooting is progressively eliminated. Simulations of idealised and realistic estuarine regimes indicate that the new parameterisation lead to results that are devoid of the runaway stratification phenomenon, as opposed to previously used models.