problem in open boundary

[javadi]

Dear users,

I try to run a upwelling_test for my domain. I have applied my grid, initial, climatology, and forcing the file to the model. The model runs without any problem. In my test case, we have one open boundary in the southern part. I think that I should define the sponge layer for the southern part. Is it correct? Or is there another solution?
Here, I guess that I should some actions to add sponge layer both in upwelling. h and upwelling. in(?). This is mainly because there is not an option in my upwelling.h about sponge layer. Which option we should add it from CPP.h?
Please guide me on how I can active the open boundary layer in the model?

Thank you so much for your interesting comments.

[kate]

What sort of open boundary do you want? In the UPWELLING case, the southern edge is in shallow water and typically has a wall. Are you changing the bathymetry? Are you providing fields on the open boundary?

I never use a sponge in the ROMS sense of the word. I do use nudging to a climatology, which some call a sponge. The ROMS sponge is a higher value of diffusivity/viscosity near the boundary - I have not found it to be helpful.

[javadi]

My region is a part of the sea. The northern part is coast similar to West and south. In the southern part, we have an open boundary with a depth between 100-120 m. Here is my upwelling.in and upwelling.h. I have not changed anything. Which open boundary is suitable for me? How should I define the open boundary in my .in file?

Please guide me

[kate]

How are you getting your ROMS information? There is both a manual and a wiki. The wiki page might help you. The manual has much the same information and also examples containing open boundaries.

[javadi]

Dear Kate
Thanks!
No. I think that I should explain more about my problem. I am a little confused although I have reviewed manual. I have changed my rupwelling.in as I have one open boundary in my southern part. After that I have faced this error there is not roms_bry.nc. Then, I have made roms_bry.nc and model run without any problem(!). Here is my terminal when showing boundaries.
My question: should I need active nudging? What is the philosophy of using nudging and sponge layers on ROMS?

Variable Grid West Edge South Edge East Edge North Edge
--------- ---- ---------- ---------- ---------- ----------

zeta 1 Closed Chapman Imp Closed Closed

ubar 1 Closed Flather Closed Closed

vbar 1 Closed Flather Closed Closed

u 1 Closed Rad + Nud Closed Closed

v 1 Closed Rad + Nud Closed Closed

temp 1 Closed Rad + Nud Closed Closed

salt 1 Closed Rad + Nud Closed Closed

[kate]

That's great that the model is running without any problems. You're all set, then, right?

You need to look at your solution to see if you are happy with it. Are you happy with it? If not, there are steps you can take to possibly improve your boundary solution, but nothing is guaranteed when it comes to open boundaries. There is the nudging right at the boundary as part of RadNud, but you can add nudging in a band assuming you have a source of fields from a larger domain, the domain providing your boundary conditions.