Bugfix on total column thickness for wetting#975
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These fixes make sense to me. I have just one suggest about a re-calculation in the barotropic solver. I've not tested yet...
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These changes should avoid encountering nonsensical values (e.g., NaNs or negative total thicknesses) when unmasked points have topography above the mean sea-level. Moreover all of the altered blocks of code have runtime options that could avoid their use. It may be worthwhile revisiting these spots in the code later to see whether a better solution is available, but for now these changes do correct some obvious problems with the code.
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In a number of cases, total resting column thickness is calucated as
G%bathyT + G%Z_ref, which is largely correct but for wetting, i.e.
G%bathyT < 0. This commit makes a correction for seven cases with this
potential bug.
There is no answer changes if no wetting points are used and G%Z_ref is
zero.
List of modules/processes affected:
* MOM_barotropic
* affects only surface stress when BT_NONLIN_STRESS is False.
* MOM_wave_speed
* h2 calculations in
* subroutine internal_tides_init
* subroutine int_tide_input_int
* subroutine tidal_mixing_init
* MOM_lateral_mixing_coeffs
* MOM_MEKE
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This PR has passed pipeline testing at https://gitlab.gfdl.noaa.gov/ogrp/mom6ci/MOM6/-/pipelines/29417. |
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The CHANNEL_DRAG option was using a harmonic mean to interpolate adjacent bottom depths at velocity points to vorticity points. However, this is not well behaved when the bottom depth is negative (i.e., above sea level), as was noted as a part of PR #975. This commit adds the new runtime parameter CHANNEL_DRAG_SHELFBREAK_DEPTH to set a depth below which a harmonic mean bottom depth is still used to mimic a continental shelfbreak profile, but above which a simple arithmetic mean is used to interpolate bathymetry to vorticity points for use with CHANNEL_DRAG. The expressions vary continuously with depth and avoid the previous problems with division by zero or a badly formed harmonic mean. By default, all answers are bitwise identical in any cases that worked previously, but cases with oceans (or Great Lakes) in basins with bottoms that are above sea-level should now work sensibly when CHANNEL_DRAG is enabled. There is a new runtime parameter in some cases.
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In a number of cases, total resting column thickness is calucated as
G%bathyT + G%z_ref, which is largely correct but for wetting, i.e.G%bathyT + G%z_ref< 0. This commit makes a correction for seven cases with this potential bug.List of modules/processes affected:
MOM_barotropicBT_NONLIN_STRESSis False.MOM_wave_speedh2calculations ininternal_tides_initint_tide_input_inttidal_mixing_initMOM_lateral_mixing_coeffsMOM_MEKEThere is no answer changes if no wetting points are used and G%Z_ref is zero.