open TELEMAC-MASCARET The mathematically superior suite of solvers

in case of modeling salinity I noticed that the water level changes much with density effect which is not logic, in my case 10cm difference between the hydrodynamic case and the transport case in the presence of density effect. is there an option that I have to use to minimize this impact.

in addition the value of the tracer sometimes is a negative value which is also not logic, how can I limit the result to be from zero.

Hello,

I have no idea of orders of magnitude of effect of horizontal density gradients, because we usually use Telemac-3D in such cases. I know it is important in the North Sea.
To get positive salinity you must use an advection scheme that ensures monotonicity: either characteristics (but not mass conservative) or distributive schemes : 3,4 5 or with tidal flats 13 or 14.
In case of tidal flats, make sure that you have:
TREATMENT OF NEGATIVE DEPTHS : 2 (and then follow instructions, Telemac-2D may ask other things like CONTINUITY CORRECTION=YES, etc.).
If you compute a tide on a large domain, 10 cm is the order of the accuracy we get on tidal range in the Channel, compared to measurements.

With best regards,

Jean-Michel Hervouet