I am running ROMS in a closed basin (Caspian Sea) using perpetual forcing to reach steady state solution but i have some strange results in net volume and zeta variables. The net volume (extracted from ROMS stout file) has decreasing trend in time (see the attached plot) and same pattern exist in the domain averaged zeta. After two years simulation domain averaged zeta value is -2.5 meter which is not realistic for this case. I though that it might be related with the forcing data but the spatial pattern of temperature and salinity looks fine when i compare with available observational data. There is no any spacial definition in CPP file,
I just need your suggestion in this point? Is this normal in a closed basin? I think this could be balanced with river forcing but i am not sure. I expect that the volume must be conserved in this case because there is no open boundary in my case. Any suggestion will be helpful. Maybe i am missing something.
Just for your information, i add the major rivers (Volga, Kura and Ural) into the model. With rough estimation, i calculated that the river discharge compensates the volume change in annual scale but i have still problem in the total net volume change. The results is still same with my previous post. I will try to test without EMINUSP option.