Regarding the freshwater flux in ROMS

[yadusharma]

Hi ROMS Developers/Users,

I wanted to add river in my model domain and the forum was very useful for giving an insight to how this is done in ROMS. But I am not clear about how the mass conservation will be taken care of by the model when river discharge is added. Any kind of suggestions will be helpful.

Thanking All

[kate]

If you're adding water through a river, you aren't going to be conserving mass. Is your river going into a lake or closed basin? If so, the water level should slowly rise, since we don't evaporate at the surface. Do you have any open boundaries? They typically don't conserve mass either, but I haven't had a problem with that (I never turn on the VOLCONS stuff).

[yadusharma]

Hi Kate,
I couldn't reply soon. I have open boundaries in my domain and rivers are entering from the grid points in the land-ocean boundary. I am using BULK_FLUXES option and also with EMINUSP. With the EMINUSP option switched on, I didn't get your point that "we don't evaporate at the surface. " . I tried with and without the VOLCONS switch. Since there was not any changes in the results, What actually this VOLCONS option is meant for?

[kate]

If your ROMS code is current, the VOLCONS switch does nothing. There are now logical switches in the ocean.in file for the four individual sides of the domain. You can conserve volume along any edge.

EMINUSP contributes to a surface salt flux and does not change the volume of water we are computing.