Fix for MASK_OUTSIDE_OBCS with MASKING_DEPTH

[kshedstrom]

The MASK_OUTSIDE_OBCS flag doesn't know about the MASKING_DEPTH and this should take care of the problem.

[Hallberg-NOAA]

These changes mirror the code setting the MASKING_DEPTH elsewhere in the MOM6 code, and they make sense to me to add them here as well.

[kshedstrom]

I am hopefully done changing things on this branch now.

[codecov]

Codecov Report

Attention: Patch coverage is 72.50000% with 11 lines in your changes missing coverage. Please review.

Project coverage is 36.65%. Comparing base (31a4d8b) to head (d59cf6d).

Files with missing lines	Patch %	Lines
src/core/MOM_open_boundary.F90	0.00%	4 Missing ⚠️
src/tracer/MOM_tracer_advect.F90	75.00%	0 Missing and 4 partials ⚠️
src/core/MOM_barotropic.F90	85.00%	0 Missing and 3 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##           dev/gfdl     #752      +/-   ##
============================================
+ Coverage     36.63%   36.65%   +0.01%     
============================================
  Files           278      278              
  Lines         84143    84182      +39     
  Branches      15833    15851      +18     
============================================
+ Hits          30826    30855      +29     
- Misses        47504    47507       +3     
- Partials       5813     5820       +7     

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[adcroft]

@kshedstrom In commit 01b0dc4 you updated the way to handle the v-direction which I think makes sense. However, you didn't change the way the u-direction is handled and left it in the form of the previous commit. I don't think this explains the MacOS fails (which @marshallward suspects is a new gnu-compiler options thing) but currently I think it breaks the rotational symmetry rule.

[adcroft]

@Hallberg-NOAA earlier approved the first version, and I agree with Bob that this seems like a good fix. However, a subsequent "better" commit broke symmetry (see #752 (comment)). This seems easy to fix (apply to u- what was done to v-) but in the mean-time I'll mark this as "changes requested".

[kshedstrom]

The symmetric version worked for EW boundaries, but not NS boundaries. The algorithm is sweeping across lines of i and is inherently non-symmetric. With non-zero turns, it would need fixing, I suppose. I'll have to investigate how the turns are actually done.

[kshedstrom]

I rotated the Supercritical test and Thomas's test and I stand by my current version. The failure is:

FAIL: Diagnostics tc3.regression.diag have changed.

One version of Thomas's test was spinning up a circulating flow while the current version has zero flow with nothing spinning it up. The previous code didn't have eta zeroed out outside the OBCs. I wouldn't be surprised if those eta values were being used somehow. Do we need to set them to some wacky value and see what happens?

[kshedstrom]

The Thomas test when rotated runs when compiled for debugging, but not when compiled for repro. It fails with:

[chinook04:2911387:0:2911387] Caught signal 11 (Segmentation fault: address not mapped to object at address (nil))
==== backtrace (tid:2911387) ====
 0 0x0000000000012d20 __funlockfile()  :0  
 1 0x0000000001183528 __mpp_domains_mod_MOD_mpp_update_domain2d_r8_3dv()  //import/c1/AKWATERS/kate/ESMG/ESMG-configs/src/FMS2/mpp/include/mpp_update_domains2D.fh:518
 2 0x0000000000a69d5e __mom_domain_infra_MOD_pass_vector_3d()  //import/c1/AKWATERS/kate/ESMG/ESMG-configs/src/MOM6/config_src/infra/FMS2/MOM_domain_infra.F90:709
 3 0x000000000067957e __mom_open_boundary_MOD_open_boundary_init()  //import/c1/AKWATERS/kate/ESMG/ESMG-configs/src/MOM6/src/core/MOM_open_boundary.F90:1941
 4 0x0000000000c17638 __mom_state_initialization_MOD_mom_initialize_state()  //import/c1/AKWATERS/kate/ESMG/ESMG-configs/src/MOM6/src/initialization/MOM_state_initialization.F90:606
 5 0x0000000000924c7b __mom_MOD_initialize_mom()  //import/c1/AKWATERS/kate/ESMG/ESMG-configs/src/MOM6/src/core/MOM.F90:2979
 6 0x00000000005a2e70 MAIN__()  //import/c1/AKWATERS/kate/ESMG/ESMG-configs/src/MOM6/config_src/drivers/solo_driver/MOM_driver.F90:280
 7 0x000000000040761d main()  //import/c1/AKWATERS/kate/ESMG/ESMG-configs/src/MOM6/config_src/drivers/solo_driver/MOM_driver.F90:27
 8 0x000000000003a7e5 __libc_start_main()  ???:0
 9 0x000000000040765e _start()  ???:0
=================================

Program received signal SIGSEGV: Segmentation fault - invalid memory reference.

The line in question is:

  if (OBC%radiation_BCs_exist_globally) call pass_vector(OBC%rx_normal, OBC%ry_normal, G%Domain, &
                     To_All+Scalar_Pair)

At this point in the run, OBC%rx_normal and ry_normal have not been allocated - when the rotation is in play, it is allocated otherwise.

[kshedstrom]

In MOM_state_initialization, there is a CS%OBC which has the r[xy]_normal allocated. There is also an OBC_in which does not have them allocated (in the rotated case).

[kshedstrom]

Also, Thomas' test is sensitive to zeroing out the outside eta, but none of the rest of my tests are. It must be something about the OBC choices he picked. As for the other issue, perhaps @marshallward knows why the rotated MOM_state_initialization gets one version of the OBC structure and the nonrotated ones get the other?

[kshedstrom]

I ran dueling debuggers and the answers do match inside the domain, spinning up a gyre and all. The Thomas test has a positive eta_outside in the Flather OBC. That drives fluid from outside to the inside. It sucks water from the point just outside the boundary, causing eta to get lower just outside the boundary without the MOM_barotropic fix, eventually making it lower than the ocean bottom.

I still stand by my fix, except for the rotational weirdness.