MOM6: +Rotationally symmetric neutral diffusion option

- NOAA-GFDL/MOM6@32f631623 +Rotationally symmetric neutral diffusion option
- NOAA-GFDL/MOM6@4fd01625b Rotation bugfixes
- NOAA-GFDL/MOM6@a23c7d8a6 fix gtracer restart repro issue with OBC
- NOAA-GFDL/MOM6@744dbcc95 Document remapping function variable units
- NOAA-GFDL/MOM6@2bc04bd76 (*)Eliminate IIm1 and JJm1 in Update_Stokes_Drift
- NOAA-GFDL/MOM6@611f575fb +(*)Fix downsample_mask indexing bugs
- NOAA-GFDL/MOM6@d311b1da1 +(*)Use z-space remapping for some diagnostics
- NOAA-GFDL/MOM6@1ae2a3a35 +(*)Refactor MOM_diag_remap for global indices
- NOAA-GFDL/MOM6@9e78615cb Earlier initialization thickness halo updates
- NOAA-GFDL/MOM6@0bd4c160b (*)Fix apply_topography_edits_from_file indexing
- NOAA-GFDL/MOM6@0ff03aea4 +Fix myStats global indexing segmentation faults
- NOAA-GFDL/MOM6@6153d97ad Compute dz in the halo for OBC segments

ice_ocean_SIS2/Baltic_ALE_z_offline_tracers/MOM_parameter_doc.all

@@ -2167,6 +2167,11 @@ NDIFF_USE_UNMASKED_TRANSPORT_BUG = False ! [Boolean] default = False
  ! If true, use an older form for the accumulation of neutral-diffusion
  ! transports that were unmasked, as used prior to Jan 2018. This is not
  ! recommended.
+NDIFF_ANSWER_DATE = 20240101 ! default = 20240101
+ ! The vintage of the order of arithmetic to use for the neutral diffusion.
+ ! Values of 20240330 or below recover the answers from the original form of the
+ ! neutral diffusion code, while higher values use mathematically equivalent
+ ! expressions that recover rotational symmetry.
 
 ! === module MOM_hor_bnd_diffusion ===
 ! This module implements horizontal diffusion of tracers near boundaries

ice_ocean_SIS2/Baltic_OM4_05/MOM_parameter_doc.all

@@ -2279,6 +2279,11 @@ NDIFF_USE_UNMASKED_TRANSPORT_BUG = False ! [Boolean] default = False
  ! If true, use an older form for the accumulation of neutral-diffusion
  ! transports that were unmasked, as used prior to Jan 2018. This is not
  ! recommended.
+NDIFF_ANSWER_DATE = 20240101 ! default = 20240101
+ ! The vintage of the order of arithmetic to use for the neutral diffusion.
+ ! Values of 20240330 or below recover the answers from the original form of the
+ ! neutral diffusion code, while higher values use mathematically equivalent
+ ! expressions that recover rotational symmetry.
 
 ! === module MOM_hor_bnd_diffusion ===
 ! This module implements horizontal diffusion of tracers near boundaries

ice_ocean_SIS2/OM4_05/MOM_parameter_doc.all

@@ -2279,6 +2279,11 @@ NDIFF_USE_UNMASKED_TRANSPORT_BUG = False ! [Boolean] default = False
  ! If true, use an older form for the accumulation of neutral-diffusion
  ! transports that were unmasked, as used prior to Jan 2018. This is not
  ! recommended.
+NDIFF_ANSWER_DATE = 20240101 ! default = 20240101
+ ! The vintage of the order of arithmetic to use for the neutral diffusion.
+ ! Values of 20240330 or below recover the answers from the original form of the
+ ! neutral diffusion code, while higher values use mathematically equivalent
+ ! expressions that recover rotational symmetry.
 
 ! === module MOM_hor_bnd_diffusion ===
 ! This module implements horizontal diffusion of tracers near boundaries

ice_ocean_SIS2/OM_1deg/MOM_parameter_doc.all

@@ -2222,6 +2222,11 @@ NDIFF_USE_UNMASKED_TRANSPORT_BUG = False ! [Boolean] default = False
  ! If true, use an older form for the accumulation of neutral-diffusion
  ! transports that were unmasked, as used prior to Jan 2018. This is not
  ! recommended.
+NDIFF_ANSWER_DATE = 20240101 ! default = 20240101
+ ! The vintage of the order of arithmetic to use for the neutral diffusion.
+ ! Values of 20240330 or below recover the answers from the original form of the
+ ! neutral diffusion code, while higher values use mathematically equivalent
+ ! expressions that recover rotational symmetry.
 
 ! === module MOM_hor_bnd_diffusion ===
 ! This module implements horizontal diffusion of tracers near boundaries

ocean_only/global_ALE/hycom/MOM_parameter_doc.all

@@ -2217,6 +2217,11 @@ NDIFF_USE_UNMASKED_TRANSPORT_BUG = False ! [Boolean] default = False
  ! If true, use an older form for the accumulation of neutral-diffusion
  ! transports that were unmasked, as used prior to Jan 2018. This is not
  ! recommended.
+NDIFF_ANSWER_DATE = 20240101 ! default = 20240101
+ ! The vintage of the order of arithmetic to use for the neutral diffusion.
+ ! Values of 20240330 or below recover the answers from the original form of the
+ ! neutral diffusion code, while higher values use mathematically equivalent
+ ! expressions that recover rotational symmetry.
 
 ! === module MOM_hor_bnd_diffusion ===
 ! This module implements horizontal diffusion of tracers near boundaries

ocean_only/global_ALE/z/MOM_parameter_doc.all

@@ -2164,6 +2164,11 @@ NDIFF_USE_UNMASKED_TRANSPORT_BUG = False ! [Boolean] default = False
  ! If true, use an older form for the accumulation of neutral-diffusion
  ! transports that were unmasked, as used prior to Jan 2018. This is not
  ! recommended.
+NDIFF_ANSWER_DATE = 20240101 ! default = 20240101
+ ! The vintage of the order of arithmetic to use for the neutral diffusion.
+ ! Values of 20240330 or below recover the answers from the original form of the
+ ! neutral diffusion code, while higher values use mathematically equivalent
+ ! expressions that recover rotational symmetry.
 
 ! === module MOM_hor_bnd_diffusion ===
 ! This module implements horizontal diffusion of tracers near boundaries

ocean_only/tracer_mixing/rho/MOM_parameter_doc.all

@@ -1625,6 +1625,11 @@ NDIFF_USE_UNMASKED_TRANSPORT_BUG = False ! [Boolean] default = False
  ! If true, use an older form for the accumulation of neutral-diffusion
  ! transports that were unmasked, as used prior to Jan 2018. This is not
  ! recommended.
+NDIFF_ANSWER_DATE = 20240101 ! default = 20240101
+ ! The vintage of the order of arithmetic to use for the neutral diffusion.
+ ! Values of 20240330 or below recover the answers from the original form of the
+ ! neutral diffusion code, while higher values use mathematically equivalent
+ ! expressions that recover rotational symmetry.
 
 ! === module MOM_hor_bnd_diffusion ===
 ! This module implements horizontal diffusion of tracers near boundaries

ocean_only/tracer_mixing/z/MOM_parameter_doc.all

@@ -1577,6 +1577,11 @@ NDIFF_USE_UNMASKED_TRANSPORT_BUG = False ! [Boolean] default = False
  ! If true, use an older form for the accumulation of neutral-diffusion
  ! transports that were unmasked, as used prior to Jan 2018. This is not
  ! recommended.
+NDIFF_ANSWER_DATE = 20240101 ! default = 20240101
+ ! The vintage of the order of arithmetic to use for the neutral diffusion.
+ ! Values of 20240330 or below recover the answers from the original form of the
+ ! neutral diffusion code, while higher values use mathematically equivalent
+ ! expressions that recover rotational symmetry.
 
 ! === module MOM_hor_bnd_diffusion ===
 ! This module implements horizontal diffusion of tracers near boundaries