Model is blowing up at coarse resolution

[Sankar]

Dear all, I am trying to set up the ROMS model over the Indian Ocean. At 1/6 degree resolution, my model is running, but at 1/4 degree resolution, it is blowing up after some time steps. I have played with the time steps from 40 to 600 secs but nothing changes except a small shift in the point (i.e., 357,146,23 when using barotropic dt = 90 and 357,146,20 when using dt = 600). As I am doing a climatology run, so u and v is almost zero in the restart file although the temp and salinity is quite okay. I also changed the viscosity values but had no luck running the model. I am using kpp vertical mixing and MIX_GEO_TS and MIX_GEO_UV. Here I am attaching some details of my log file. It will be great if anyone can help me in this prospect.

[yuchengzhang]

It seems that the blew up is happening near the boundary for w, I had a similar problem and I think there were huge bathymetry differences near that point. It was solved by adding a sponge layer.

[Sankar]

Thanks yuchengzhang for your quick response. But can you please tell me how to add a sponge layer in bathymetry. I mean I have to add the sponge layer in the tool where I have made the grid file.

[yuchengzhang]

Thanks yuchengzhang for your quick response. But can you please tell me how to add a sponge layer in bathymetry. I mean I have to add the sponge layer in the tool where I have made the grid file.

Here is the link,
https://www.myroms.org/projects/src/ticket/627

[Sankar]

Yeah, currently I am looking at the Matlab file sponge.m following the link for calculating the visc_factor. Hope to sort it out soon. Thanks for your reply.