Possible bug in nesting.F for 2D apps with wetting/drying

[stef]

Hi,

This is unrelated to the incorrect netcdf header reproduced in the wiki (as reported earlier in viewtopic.php?f=17&t=5425 ), but it's related to nesting in general.

In 2-d applications with wetting/drying, the u/vmasks supplied to fine2coarse2d() are in their multi-valued form (-1,1,0,2 depending on whether the cell itself and its neighbour are dry). Then u/vbar are multiplied by MIN(1,mask), which can be -1. If I understand the code correctly, the masks applied in this routine should generally be in a binary form (0 or 1).

I think this applies to both Rutgers and COAWST. I can see a difference between Rutgers and COAWST in nesting.F regarding the rmasks (rmask vs rmask_full), but I'm not sure how that relates to the problem with the u/vmasks.

I think that in 3d applications, the multi-valued form of the u/v wetmasks is converted to binary form after the fast time-stepping.

I wonder if in 2d applications, the multi-valued mask can just be converted to a binary mask like so:

0 if the multi-valued mask is 0
1 if the multi-valued mask is -1,1 or 2

The rationale is that at all locations where the flux delimiter was applied in the previous step2d, u/vbar should have been set to 0 already. So there is no need to do this again in nesting.F. Not sure if this makes sense physically? What do you think?

Thanks for your help!

Regards, Stefan

[stef]

I wonder if in 2d applications, the multi-valued mask can just be converted to a binary mask like so

I mean only in fine2coarse2d(), not elsewhere....