A new parameterisation of salinity advection to prevent stratification from running away in a simple estuarine model

S. Blaise (1) , E. Deleersnijder (1)

1 UCL - Université Catholique de Louvain = Catholic University of Louvain

A new parameterisation of horizontal salinity advection 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 numerical artefact 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 artefact, as opposed to previously used models.

Domaines: Océan, Atmosphère

S. Blaise, E. Deleersnijder. A new parameterisation of salinity advection to prevent stratification from running away in a simple estuarine model. Ocean Science Discussions, 2008, 5 (2), pp.187-211. ⟨hal-00298500⟩