Lateral boundary condition BC - Flather FlaNud?

[l_fr]

Hello,

I was previously using ROMS 3.2 and defined in the header file the options, for example SOUTH_M2FLATHER and SOUTH_M2NUDGING for the south 2D-momentum boundary condition set to flather and nudging.
Now using ROMS 3.6 and the new way to provide lateral boundary conditions in the ocean.in file, I'm able to use RadNud, which combines Rad and Nud, but not FlaNud, I get the following error:
INP_PAR - illegal lateral boundary condition keyword: FlaNud
LBC(isUbar) == FlaNud FlaNud Clo Clo ! 2D U-momentum
Does this mean that this possibility is not yet implemented? Or am I writing it wrong?

[arango]

No, we never have *_M2NUDGING with the *_FLATHER option for open boundary conditions in any version of ROMS. The nudging is only done in the radiation conditions. So I don't know what you are talking about. ROMS is giving you the right error because this is not available neither implemented for this type of open boundary conditions.

Notice that the documentation says: The keyword RadNud implies radiation boundary condition with nudging. This combination is usually used in active/passive radiation conditions. However, this logic facilitates such a combination with other boundary conditions in the future, but it has not been implemented yet.

[l_fr]

Thank you for your quick reply. I guess I made a mistake in my previous header files then.

Happy modelling,

François

[tony1230]

Hi l_fr

I have post in thread viewtopic.php?f=14&t=2454

John gave a detailed illumination on this. It may help you.

-shou

[l_fr]

Thank you Shou,

This thread indeed gave me lots of elements of answer and comprehension!

François