Add Black Sea blockage

[xylar]

This feature makes sure that the Black Sea is not included in MPAS meshes (as long as they use critical passages and critical land blockages, which high resolution meshes typically do not).

[xylar]

@maltrud, @milenaveneziani, @jonbob and @mark-petersen, just take a look at this:
https://github.com/xylar/geometric_features/blob/add_black_sea_blockage/geometric_data/ocean/transect/Black_Sea_Blockage/transect.geojson
and let me know if you agree that this should be blocked off. Nothing else needed for your review for now.

[jonbob]

@xylar - does it also get rid of the Caspian?

[xylar]

I don't see any way the Caspian Sea would ever connect to the open ocean. If it were through the Black Sea, then yes this would block it, too. Do you know of meshes where it wasn't culled?

[jonbob]

I think it's always been through the Black Sea, so this should take care of it. I just wasn't picturing it from the blockage transect

[jonbob]

Looks good from visual inspection

[mark-petersen]

Yes, looks good. Thanks!

[xylar]

@milenaveneziani and @maltrud, do you want to review this? It takes quite a bit of work to update geometric_features and compass so these changes make it into meshes, and I'd like to get started on that as soon as I can.

[xylar]

@vanroekel, would you also give it a look?

[vanroekel]

changes look good to me. Approved via visual inspection

[xylar]

I did a run with the mesh MPAS-Dev/MPAS-Model#518 using a compass environment with this version of geometric features. I verified that the Black Sea blockage is being included along with the 4 other blockages and that the mesh doesn't have the Black Sea (though this is not because of the blockage in this case).