Mediterranean Sea Model setup advises

[ThanosG]

Dear ROMS users,

I am trying to set up an experiment for the Mediterranean Sea. The model setup is based on the Fjord experiment with numerous changes. For the time being, I use monthly T and S boundary and initial conditions based on Medatlas. My setup can be seen in the .h and .in files that I attach.
What I can see after a 3 months run, is that I cannot increase the time step more than 240s because it blows up, so my current set up must be unstable.
Another thing is the circulation pattern. After a three months run, I can’t get the eastward circulation at the southern part of the Med. It is like that the eastward current does not circulate with consistency. It is way too weak at the point to have counter currents. I could attach some figures for assistance.
So I suspect that it is a matter of Physics and by that I mean that either my definitions (.h) are not correct, or it just doesn't read correctly the boundary conditions.
So dear users, every help is more than welcome.

Best regards,
Thanos

[jivica]

From your .h file I can see that you do not have realistic atmo forcing, you do not have river forcing, etc ...
It is hard to expect model to reproduce physical features if not using physical assumptions.
To get correct dynamics in the Adriatic I use 39 river sources, realistic as possible atmo forcing, boundary conditions etc...
Check on the MyOcean and see MFS...
Cheers,
Ivica

[ThanosG]

Dear Ivica,

Thanks for your prompt reply! But why when using POM model, with only boundary and initial conditions from medatlas, I get the classic features of the Med circulation after a month’s run? My forcing fields are just zeros and I have no river inputs indeed. I would like to proceed step by step.
You didn’t notice any bad physics in my setup, something that slips my mind and that could cause very slow advection and diffusion? I would also like to state that I have changed the SmagorCoef from 0.1 to 1.0.

Best,
Thanos

[jivica]

OK, looking into .h more deeply I can notice that
you use central 2nd order for advection, why not standard upwind 3rd order is there some specific reason for C2?
you can add diffusion and/or viscosity within ocean.in...
If you want more/less temp/salt conservative then use MPDATA, I do not use smagorinsky at all,
to speed up things I can send you .h file that I use and then just strip down forcing part.
Send me email.
Ivica

[ThanosG]

Dear Ivica,

I appreciate your help! My email is thganasos@hcmr.gr

Thanks once again,
Thanos

[ThanosG]

Dear Ivica,

Your help was enormous. Thank you for your time and patience!

Best regards,
Thanos