[MITgcm-support] Prescribe eta as open boundary condition

[Matthew Mazloff]

Hello,

I believe prescribing an inflow in the form of a barotropic wave will  
be sufficient.  Try giving an oscillating normal flow -- eta will be  
determined by continuity.  And make the sponge layer large enough and  
strong enough to absorb the reflection.

-Matt





On Oct 21, 2010, at 7:48 AM, Eivind Støylen wrote:

> Dear all,
> This may be an old problem, I have seen it discussed in mails some  
> years
> back, but I would appreciate an updated answer on the following.
>
> I am simulating a 3D stratified fjord with a sill and one open  
> boundary.
> On this boundary I want forcing in terms of barotropic tide, in  
> order to
> analyse the baroclinic tide response inside the fjord. The most
> "realistic" forcing would then in my opinion be to apply open boundary
> forcing in terms of oscillating surface, i.e. setting  
> OBWeta=Acos(omega*t)
> in obcs_calc.F. (Ive made some attempts with prescribed velocity 
> +sponge,
> but as the prescribed velocities are merely guesses, the result isnt  
> very
> realistic..).
>
> How should I proceed to do this? Do I need to turn on NONLIN_FRSURF?
> Seeing as eta is calculated from the divergence of the flow I fear I  
> need
> some extensive code manipulation here...
>
> Regards,
> Eivind Støylen
> PhD student
> University of Oslo,
> Norway
>
>
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