Skip to content

Commit

Permalink
+Replace KVML with KV_ML_INVZ2
Browse files Browse the repository at this point in the history 
  Renamed the runtime parameter KVML with KV_ML_INVZ2 and modified the comments
describing it to more clearly indicate what it does and to explicitly discourage
its use. Specifying KVML will still give identical results, but is no longer
logged and triggers a warning message if it is used.  The two descriptions of
the HBBL runtime parameter in MOM_vert_friction and MOM_set_viscosity were also
made consistent.  Also added units to several comments describing real variables
and corrected some spelling errors in comments in MOM_vert_friction.F90.  This
commit leads to changes in the entries of several MOM_parameter_doc files, but
all existing solutions are bitwise identical.
  • Loading branch information
@Hallberg-NOAA
Hallberg-NOAA committed Sep 2, 2022
1 parent fa6d8e3 commit 4ca424a
Show file tree
Hide file tree
Showing 2 changed files with 46 additions and 26 deletions.
10 changes: 5 additions & 5 deletions src/parameterizations/vertical/MOM_set_viscosity.F90
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2110,11 +2110,11 @@ subroutine set_visc_init(Time, G, GV, US, param_file, diag, visc, CS, restart_CS
endif

call get_param(param_file, mdl, "HBBL", CS%Hbbl, &
"The thickness of a bottom boundary layer with a "//&
"viscosity of KVBBL if BOTTOMDRAGLAW is not defined, or "//&
"the thickness over which near-bottom velocities are "//&
"averaged for the drag law if BOTTOMDRAGLAW is defined "//&
"but LINEAR_DRAG is not.", units="m", fail_if_missing=.true.) ! Rescaled later
"The thickness of a bottom boundary layer with a viscosity increased by "//&
"KV_EXTRA_BBL if BOTTOMDRAGLAW is not defined, or the thickness over which "//&
"near-bottom velocities are averaged for the drag law if BOTTOMDRAGLAW is "//&
"defined but LINEAR_DRAG is not.", &
units="m", fail_if_missing=.true.) ! Rescaled later
if (CS%bottomdraglaw) then
call get_param(param_file, mdl, "CDRAG", CS%cdrag, &
"CDRAG is the drag coefficient relating the magnitude of "//&
Expand Down
62 changes: 41 additions & 21 deletions src/parameterizations/vertical/MOM_vert_friction.F90
View file
Original file line number Diff line number Diff line change
Expand Up @@ -96,10 +96,10 @@ module MOM_vert_friction
real :: harm_BL_val !< A scale to determine when water is in the boundary
!! layers based solely on harmonic mean thicknesses
!! for the purpose of determining the extent to which
!! the thicknesses used in the viscosities are upwinded.
!! the thicknesses used in the viscosities are upwinded [nondim].
logical :: direct_stress !< If true, the wind stress is distributed over the topmost Hmix_stress
!! of fluid, and the added mixed layer viscosity from KVML or a more
!! realistic viscosity parameterization is not needed for stability.
!! of fluid, and an added mixed layer viscosity or a physically based
!! boundary layer turbulence parameterization is not needed for stability.
logical :: dynamic_viscous_ML !< If true, use the results from a dynamic
!! calculation, perhaps based on a bulk Richardson
!! number criterion, to determine the mixed layer
Expand Down Expand Up @@ -154,7 +154,7 @@ module MOM_vert_friction
!! is the <em>interfacial coupling thickness per time step</em>,
!! encompassing background viscosity as well as contributions from
!! enhanced mixed and bottom layer viscosities.
!! $r_k$ is a Rayleight drag term due to channel drag.
!! $r_k$ is a Rayleigh drag term due to channel drag.
!! There is an additional stress term on the right-hand side
!! if DIRECT_STRESS is true, applied to the surface layer.

Expand Down Expand Up @@ -302,7 +302,7 @@ subroutine vertvisc(u, v, h, forces, visc, dt, OBC, ADp, CDp, G, GV, US, CS, &
! denote the diagonal of the system as b_k, the subdiagonal as a_k
! and the superdiagonal as c_k. The right-hand side terms are d_k.
!
! ignoring the rayleigh drag contribution,
! ignoring the Rayleigh drag contribution,
! we have a_k = -dt_Z_to_H * a_u(k)
! b_k = h_u(k) + dt_Z_to_H * (a_u(k) + a_u(k+1))
! c_k = -dt_Z_to_H * a_u(k+1)
Expand Down Expand Up @@ -717,11 +717,11 @@ subroutine vertvisc_coef(u, v, h, forces, visc, dt, G, GV, US, CS, OBC)
real, allocatable, dimension(:,:,:) :: Kv_v !< Total vertical viscosity at v-points [Z2 T-1 ~> m2 s-1].
real :: zcol(SZI_(G)) ! The height of an interface at h-points [H ~> m or kg m-2].
real :: botfn ! A function which goes from 1 at the bottom to 0 much more
! than Hbbl into the interior.
! than Hbbl into the interior [nondim].
real :: topfn ! A function which goes from 1 at the top to 0 much more
! than Htbl into the interior.
! than Htbl into the interior [nondim].
real :: z2 ! The distance from the bottom, normalized by Hbbl [nondim]
real :: z2_wt ! A nondimensional (0-1) weight used when calculating z2.
real :: z2_wt ! A nondimensional (0-1) weight used when calculating z2 [nondim].
real :: z_clear ! The clearance of an interface above the surrounding topography [H ~> m or kg m-2].
real :: a_cpl_max ! The maximum drag coefficient across interfaces, set so that it will be
! representable as a 32-bit float in MKS units [Z T-1 ~> m s-1]
Expand All @@ -730,7 +730,7 @@ subroutine vertvisc_coef(u, v, h, forces, visc, dt, G, GV, US, CS, OBC)

real :: I_valBL ! The inverse of a scaling factor determining when water is
! still within the boundary layer, as determined by the sum
! of the harmonic mean thicknesses.
! of the harmonic mean thicknesses [nondim].
logical, dimension(SZIB_(G)) :: do_i, do_i_shelf
logical :: do_any_shelf
integer, dimension(SZIB_(G)) :: &
Expand Down Expand Up @@ -1163,7 +1163,7 @@ subroutine find_coupling_coef(a_cpl, hvel, do_i, h_harm, bbl_thick, kv_bbl, z_i,
u_star, & ! ustar at a velocity point [Z T-1 ~> m s-1].
absf, & ! The average of the neighboring absolute values of f [T-1 ~> s-1].
! h_ml, & ! The mixed layer depth [H ~> m or kg m-2].
nk_visc, & ! The (real) interface index of the base of mixed layer.
nk_visc, & ! The (real) interface index of the base of mixed layer [nondim].
z_t, & ! The distance from the top, sometimes normalized
! by Hmix, [H ~> m or kg m-2] or [nondim].
kv_TBL, & ! The viscosity in a top boundary layer under ice [Z2 T-1 ~> m2 s-1].
Expand Down Expand Up @@ -1694,8 +1694,9 @@ subroutine vertvisc_init(MIS, Time, G, GV, US, param_file, diag, ADp, dirs, &
"LINEAR_DRAG.", default=.true.)
call get_param(param_file, mdl, "DIRECT_STRESS", CS%direct_stress, &
"If true, the wind stress is distributed over the topmost HMIX_STRESS of fluid "//&
"(like in HYCOM), and the added mixed layer viscosity from KVML or another "//&
"more realistic parameterization is not needed for stability.", default=.false.)
"(like in HYCOM), and an added mixed layer viscosity or a physically based "//&
"boundary layer turbulence parameterization is not needed for stability.", &
default=.false.)
call get_param(param_file, mdl, "DYNAMIC_VISCOUS_ML", CS%dynamic_viscous_ML, &
"If true, use a bulk Richardson number criterion to "//&
"determine the mixed layer thickness for viscosity.", &
Expand Down Expand Up @@ -1745,14 +1746,33 @@ subroutine vertvisc_init(MIS, Time, G, GV, US, param_file, diag, ADp, dirs, &
"The molecular value, ~1e-6 m2 s-1, may be used.", &
units="m2 s-1", fail_if_missing=.true., scale=US%m2_s_to_Z2_T, unscaled=Kv_dflt)

if (GV%nkml < 1) call get_param(param_file, mdl, "KVML", CS%Kvml_inv2, &
"The extra kinematic viscosity in a mixed layer of thickness HMIX_FIXED, "//&
"with the actual viscosity scaling as 1/(z*HMIX_FIXED)^2 to allow for finite "//&
"wind stresses to be transmitted through infinitessimally thin surface layers. "//&
"This is an older option for numerical convenience without a strong physical "//&
"basis, and its use is now discouraged. KVML is not used if BULKMIXEDLAYER "//&
"is true.", &
units="m2 s-1", default=Kv_dflt, scale=US%m2_s_to_Z2_T, do_not_log=(GV%nkml>0))
if (GV%nkml < 1) then
call get_param(param_file, mdl, "KV_ML_INVZ2", CS%Kvml_inv2, &
"An extra kinematic viscosity in a mixed layer of thickness HMIX_FIXED, "//&
"with the actual viscosity scaling as 1/(z*HMIX_FIXED)^2, where z is the "//&
"distance from the surface, to allow for finite wind stresses to be "//&
"transmitted through infinitesimally thin surface layers. This is an "//&
"older option for numerical convenience without a strong physical basis, "//&
"and its use is now discouraged.", &
units="m2 s-1", default=-1.0, scale=US%m2_s_to_Z2_T, do_not_log=.true.)
if (CS%Kvml_inv2 < 0.0) then
call get_param(param_file, mdl, "KVML", CS%Kvml_inv2, &
"The scale for an extra kinematic viscosity in the mixed layer", &
units="m2 s-1", default=Kv_dflt, scale=US%m2_s_to_Z2_T, do_not_log=.true.)
if (CS%Kvml_inv2 >= 0.0) &
call MOM_error(WARNING, "KVML is a deprecated parameter. Use KV_ML_INVZ2 instead.")
endif
if (CS%Kvml_inv2 < 0.0) CS%Kvml_inv2 = CS%Kv ! Change this default later to 0.0.
call log_param(param_file, mdl, "KV_ML_INVZ2", US%Z2_T_to_m2_s*CS%Kvml_inv2, &
"An extra kinematic viscosity in a mixed layer of thickness HMIX_FIXED, "//&
"with the actual viscosity scaling as 1/(z*HMIX_FIXED)^2, where z is the "//&
"distance from the surface, to allow for finite wind stresses to be "//&
"transmitted through infinitesimally thin surface layers. This is an "//&
"older option for numerical convenience without a strong physical basis, "//&
"and its use is now discouraged.", &
units="m2 s-1", default=Kv_dflt)
endif

if (.not.CS%bottomdraglaw) then
call get_param(param_file, mdl, "KV_EXTRA_BBL", CS%Kv_extra_bbl, &
"An extra kinematic viscosity in the benthic boundary layer. "//&
Expand All @@ -1764,7 +1784,7 @@ subroutine vertvisc_init(MIS, Time, G, GV, US, param_file, diag, ADp, dirs, &
"KV_EXTRA_BBL is not used if BOTTOMDRAGLAW is true.", &
units="m2 s-1", default=US%Z2_T_to_m2_s*CS%Kv, scale=US%m2_s_to_Z2_T, do_not_log=.true.)
if (abs(Kv_BBL - CS%Kv) > 1.0e-15*abs(CS%Kv)) then
call MOM_error(WARNING, "KVBBL is a depricated parameter. Use KV_EXTRA_BBL instead.")
call MOM_error(WARNING, "KVBBL is a deprecated parameter. Use KV_EXTRA_BBL instead.")
CS%Kv_extra_bbl = Kv_BBL - CS%Kv
endif
endif
Expand Down

0 comments on commit 4ca424a

Please sign in to comment.