Hi all,
I have a question about open boundary conditions. There are many options to use in ROMS. However, I still don't know which combination of open boundary conditions is good for some general cases. For example, let's think about an estuary which has a river inflow from west and other boundary(east) reaches sea. Let's assume there are no Coriolis, no winds and no tides; there only exists river inflow. In this case we don't know velocity and surface elevation at the open boundary. With this simple example I used several combination of open boundary conditions. And I got only reasonable result with FSGRADIENT & M2GRADIENT & M3GRADIENT & TGRADIENT combination. Is this a good combination for this simple case or not? Somebody suggested me to use FSCHAPMAN & M2FLATHER & M3RADIATION combination. Then I have to define both FS_OBC and M2_OBC. How do I define water surface elevation and velocity at the open boundary; this is a ideal case and don't have any data at the open boundary. What if I have tides at the open boundary? In this case, I used clamped condition for free surface and M2_REDUCED condition. I know clamped condition is not good enough for this case because it reflect wave into the domain. Then which condition should I use if I only know the tidal elevation? Does anybody know any good reference for these case? or other simple cases? Any comment will be appreciated.
Thanks,
Jungwoo