MOHID Forum

Dear all, I think we need to do a small discussion about concepts. For a numerical modeler what exits is the position of sea surface that is compute using a 2D mass balance equation where from the divergence of the barotropic flow you compute the time derivative of the sea surface. The oceanographer...

The idea is to force the model using the gradients of the radiation stresses that come out from standard spectral models like Swan or Stwave. I recommend the paper http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VBJ-4VR24B4-1&_user=972035&_coverDate=02%2F28%2F2009&_alid=87...

In the hydrodynamic input file you have

Baroclinic : 1

it should be

BAROCLINIC : 1

The model is case sensitive

The baroclinic force is disconnected in your model. The baroclinic force is the one responsible for the process described by you.

Regards,
Paulo

Hi Samantha,
this a quite unusual problem. Please check the coordinate system used in your grid and check the bathymetry. For me this is only possible if you have a big mistake in the bathymetry definition.

Paulo.

This is an interesting question. The inverse barometer by it self is not a forcing mechanism (water is approximately incompressible). Mohid is prepared to be forced by the term (-dpatm/dx, -dpatm/dy). MOHID can be forced with the gradients of atmospheric pressure. The options you connect was to acti...

The Hydrodynamic model of Mohid very robust but when there is a problem this is the typical error. Look at the courant number that the model sends as message to screen this value should be lower than 8 specially in enclose areas with channels. In open ocean can be a little bit bigger. Look at the ba...

Go to

http://www.mohid.com/wiki/index.php?tit ... ata_File_2

Check if you are not given the same name to two stations. In this case the model will have a problem similar to the one describe by you.

Paulo

The answer is no. the idea in the future is to have two-way sub-models. This will be similar to quadtree grids. For now we only have a one-way sub-models.

Paulo

Hello,

the correct approach is to start the father and son model at the same time. What you suggest is not a good idea because the son model will start from rest with a boundary condition fully develop. This will in the majory of the applications give bad results.

Paulo

Hi,

in general mohid uses SI units. The sedimentation velocity is in m/s.

Paulo

What is the courant number of your application ? This is one of the information that the model write for the screen.
Paulo

As a general rule is always a good ideia do put far way the open boundary. If you are using clamped boundary conditions (imposed sea surface level) you might have problems in the cells where the open bounrady intersects land. Try to put you open boundary where depths are big and velocities are low. ...

I think this is an old problem with the cartesian geometry. If you are using a cartesian geometry you must be sure that the sum of all layers are equal or bigger than the max depth of the bathymetry. This is an old problem that I have not yet found a cleaver way to solve it.

Paulo

This is a old keyword that was replace by the keyword 'LOCAL_SOLUTION'.

this last keyword is used to specify how the external solution is specified (nesting, tidal gauges, via assimulation module, etc.).

Paulo