Stochastic Physics Fixes

CONTRIBUTORS.md

@@ -5,3 +5,4 @@
 | james-bruten-mo | James Bruten | Met Office | 2025-12-09 |
 | jennyhickson | Jenny Hickson | Met Office | 2025-12-10 |
 | mo-marqh | mark Hedley | Met Office | 2025-12-11 |
+| tommbendall | Thomas Bendall | Met Office | 2025-01-15 |

dependencies.yaml

@@ -30,8 +30,8 @@ lfric_apps:
     ref:
 
 lfric_core:
-    source: git@github.com:MetOffice/lfric_core.git
-    ref: 2025.12.1
+    source: git@github.com:tommbendall/lfric_core.git
+    ref: TBendall/FixW0WthFilter
 
 moci:
     source: git@github.com:MetOffice/moci.git

interfaces/physics_schemes_interface/rose-meta/um-stochastic_physics/HEAD/rose-meta.conf

@@ -827,7 +827,8 @@ values='fd','fe'
 [namelist:stochastic_physics=skeb_level_bottom]
 compulsory=true
 description=Bottom level of SKEB calculations
-help=Bottom level of SKEB calculations - model level a little above surface
+help=The bottom pressure-level at which SKEB is active.
+    =A value of 1 corresponds to the lowest level of the model.
 ns=namelist/Science/Stochastic Physics/SKEB
 range=2:60
 sort-key=Panel-A3a
@@ -845,7 +846,7 @@ type=integer
 [namelist:stochastic_physics=skeb_level_top]
 compulsory=true
 description=Top level of SKEB calculations
-help=Top level of SKEB calculations - model level at or just above tropopause
+help=If the model has N layers, a value of N would correspond to the top layer.
 ns=namelist/Science/Stochastic Physics/SKEB
 range=30:200
 sort-key=Panel-A3b
@@ -963,25 +964,29 @@ type=integer
 
 [namelist:stochastic_physics=spt_level_bottom]
 compulsory=true
-description=Bottom level where SPT is active
-           =See Help panel for details
-help=Bottom level wehre SPT perturbations are applied.
-    =Though, the tapering at this level is 0 so effectively
-    =SPT perturbations start one level above, see help-panel
-    = of spt_level_begin_tapering_bottom.
+description=Bottom level at which SPT is active
+help=The bottom theta-level at which SPT perturbations are applied.
+    =A value of 0 would correspond to the surface, so a value of 2 means that
+    =perturbations are applied from the third theta-level and above.
+    =Note that the perturbations are actually tapered, so that at the level
+    =specified here the perturbations will still be 0, and SPT perturbations
+    =effectively start at one level above this specified value.
+    =For more information, see help-panel of spt_level_begin_tapering_bottom.
 ns=namelist/Science/Stochastic Physics/SPT
 range=2:60
 sort-key=Panel-A6a
 type=integer
 
 [namelist:stochastic_physics=spt_level_top]
 compulsory=true
-description=Top level where SPT is active
-           =See Help panel for details
-help=Top level where SPT perturbations are applied.
+description=Top level at which SPT is active
+help=The top theta-level at which SPT perturbations are applied.
+    =If the model has N layers, a value of N would correspond to the top
+    =boundary. Note that the perturbations are actually tapered, so that at the
+    =level specified here the perturbations will still be 0, and SPT
+    =perturbations effectively start at one level below this specified value.
     =Though, the tapering at this level is 0 so effectively
-    =SPT perturbations start one level below, see help-panel
-    = of spt_level_begin_tapering_top.
+    =For more information, see help-panel of spt_level_begin_tapering_top.
 ns=namelist/Science/Stochastic Physics/SPT
 range=30:200
 sort-key=Panel-A6d

interfaces/physics_schemes_interface/source/algorithm/skeb_main_alg_mod.x90

@@ -296,6 +296,10 @@ module skeb_main_alg_mod
   ! Iterators in for loops
   integer(i_def) :: m, n, n_row, stencil_extent
 
+  ! SKEB calculations are performed at cell centres (W3 points). To index the
+  ! "eta_theta_levels" array correctly at these points, set offset to 1
+  integer(kind=i_def), parameter :: lev_offset = 1
+
   !!!!!!!!!! END OF VARIABLE DEFINITION, START OF CODE !!!!!!!!!!
   if ( subroutine_timers ) call timer("skeb_main_alg")
 
@@ -378,10 +382,10 @@ module skeb_main_alg_mod
   end if
 
   !!!!!! 1.b call stph_fp_main to create forcing pattern for SKEB
-  call stph_fp_main_alg(skeb_level_bottom-1_i_def, skeb_level_top-1_i_def, &
-                        stph_n_min, stph_n_max, stph_spectral_dim,         &
-                        skeb_alpha, skeb_power_law,                        &
-                        skeb_spectral_coeffc, skeb_spectral_coeffs,        &
+  call stph_fp_main_alg(skeb_level_bottom-1_i_def, skeb_level_top-1_i_def,     &
+                        lev_offset, stph_n_min, stph_n_max, stph_spectral_dim, &
+                        skeb_alpha, skeb_power_law,                            &
+                        skeb_spectral_coeffc, skeb_spectral_coeffs,            &
                         fp_skeb)
 
   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

interfaces/physics_schemes_interface/source/algorithm/spt_main_alg_mod.x90

@@ -223,6 +223,10 @@ module spt_main_alg_mod
   ! iterators in for loops
   integer(i_def) :: n,n_row, m
 
+  ! SPT calculations are performed at theta-levels (Wtheta points). To index the
+  ! "eta_theta_levels" array correctly at these points, set offset to 0
+  integer(kind=i_def), parameter :: lev_offset = 0
+
   if ( subroutine_timers ) call timer("spt_main_alg")
 
   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
@@ -284,10 +288,10 @@ module spt_main_alg_mod
   call invoke( setval_c(fp_spt, 0.0_r_def))
 
   ! Create forcing pattern for SPT
-  call stph_fp_main_alg(spt_level_bottom, spt_level_top,          &
-                        1, stph_n_max, stph_spectral_dim,         &
-                        spt_alpha, spt_power_law,                 &
-                        spt_spectral_coeffc, spt_spectral_coeffs, &
+  call stph_fp_main_alg(spt_level_bottom, spt_level_top, lev_offset, &
+                        1, stph_n_max, stph_spectral_dim,            &
+                        spt_alpha, spt_power_law,                    &
+                        spt_spectral_coeffc, spt_spectral_coeffs,    &
                         fp_spt)
 
   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

interfaces/physics_schemes_interface/source/algorithm/stph_fp_main_alg_mod.x90

@@ -47,6 +47,12 @@ module stph_fp_main_alg_mod
 
   !>@param[in]         level_bottom            Bottom level of the stochastic scheme
   !>@param[in]         level_top               Top level of the stochastic scheme
+  !>@param[in]         level_offset            Level offset. This routine can be
+  !!                                           applied at W3 and Wtheta points,
+  !!                                           but both implementations index
+  !!                                           from the same "eta_theta_levels"
+  !!                                           array, so need an offset to index
+  !!                                           correctly. Set 0 Wtheta, 1 for W3
   !>@param[in]         wavenumber_min          Minimum wavenumber applied to build the FP
   !>@param[in]         wavenumber_max          Maximum wavenumber applied to build the FP
   !>@param[in]         spectral_dim            Dimension of spectral coeffients arrays
@@ -56,10 +62,10 @@ module stph_fp_main_alg_mod
   !>@param[in,out]     spectral_coeffs         Imaginary Spectral coefficients
   !>@param[i,out]      fp                      Forcing pattern
 
-  subroutine stph_fp_main_alg(level_bottom, level_top,          &
-                              wavenumber_min, wavenumber_max,   &
-                              spectral_dim, alpha, power_law,   &
-                              spectral_coeffc, spectral_coeffs, &
+  subroutine stph_fp_main_alg(level_bottom, level_top, level_offset, &
+                              wavenumber_min, wavenumber_max,        &
+                              spectral_dim, alpha, power_law,        &
+                              spectral_coeffc, spectral_coeffs,      &
                               fp)
 
   ! TO DO after PSyclone ticket 1312
@@ -79,8 +85,8 @@ module stph_fp_main_alg_mod
 
   !!!! Arguments
   ! Scalars with scheme levels, wavenumbers and spectral dimensions
-  integer(kind=i_def), intent(in) :: level_bottom, level_top,          &
-                                     wavenumber_min, wavenumber_max,   &
+  integer(kind=i_def), intent(in) :: level_bottom, level_top, level_offset,    &
+                                     wavenumber_min, wavenumber_max,           &
                                      spectral_dim
 
   ! spectral coefficients power law and decorrelation
@@ -151,12 +157,13 @@ module stph_fp_main_alg_mod
       my_phi_stph = ATAN2(spectral_coeffs(n_row+m), &
                           spectral_coeffc(n_row+m))
       ! Max shift ranges from 0 <-> pi  for wavenos 1 <-> wavenumber_max
-      my_phishft_stph = (wavenumber_max - max(n,m)) * pi / (wavenumber_max-1)
+      my_phishft_stph = (wavenumber_max - max(n,m)) * pi                       &
+                        / (wavenumber_max - wavenumber_min)
 
       do k = level_bottom, level_top
 
           ! Apply vertical scaling Level 1 = no change -> 12km Level = max change (=pi)
-          kr = (domain_height*eta_theta_levels(k))/12.0e3_r_def
+          kr = (domain_height*eta_theta_levels(k + level_offset))/12.0e3_r_def
 
           ! Create coeff with phase shift
           coeffc_phase(k, n_row+m) = my_coeff_rad * cos(my_phi_stph +    &

rose-stem/site/meto/kgos/lfric_atm/azspice/checksum_lfric_atm_clim_gal9-C12_azspice_gnu_fast-debug-32bit.txt

@@ -1,9 +1,9 @@
-Inner product checksum rho =         46D66411
-Inner product checksum theta =         518E95C2
-Inner product checksum u =         6AF4A509
-Inner product checksum mr1 =         3FD1977C
-Inner product checksum mr2 =         375C8794
-Inner product checksum mr3 =         3534A85C
-Inner product checksum mr4 =         36B9C166
+Inner product checksum rho =         46D66391
+Inner product checksum theta =         518E960E
+Inner product checksum u =         6AF41D3E
+Inner product checksum mr1 =         3FD1EF1A
+Inner product checksum mr2 =         3744B62D
+Inner product checksum mr3 =         353557CA
+Inner product checksum mr4 =         36C14665
 Inner product checksum mr5 =                0
 Inner product checksum mr6 =                0

rose-stem/site/meto/kgos/lfric_atm/azspice/checksum_lfric_atm_clim_gal9_chem-C12_azspice_gnu_fast-debug-32bit.txt

@@ -1,9 +1,9 @@
-Inner product checksum rho =         46D66282
-Inner product checksum theta =         518E9697
-Inner product checksum u =         6AF4EDB0
-Inner product checksum mr1 =         3FD1A816
-Inner product checksum mr2 =         372DA48E
-Inner product checksum mr3 =         355FEEE4
-Inner product checksum mr4 =         36BADA78
+Inner product checksum rho =         46D66988
+Inner product checksum theta =         518E9953
+Inner product checksum u =         6AF43368
+Inner product checksum mr1 =         3FD1683B
+Inner product checksum mr2 =         3745B57B
+Inner product checksum mr3 =         352B1260
+Inner product checksum mr4 =         36B980D2
 Inner product checksum mr5 =                0
 Inner product checksum mr6 =                0

rose-stem/site/meto/kgos/lfric_atm/ex1a/checksum_lfric_atm_clim_gal9-C12_ex1a_cce_fast-debug-32bit.txt

@@ -1,9 +1,9 @@
-Inner product checksum rho =         46D6652A
-Inner product checksum theta =         518E93EC
-Inner product checksum u =         6AF54A1D
-Inner product checksum mr1 =         3FD199FC
-Inner product checksum mr2 =         373A4F06
-Inner product checksum mr3 =         35526759
-Inner product checksum mr4 =         36CD3F45
+Inner product checksum rho =         46D6654E
+Inner product checksum theta =         518E92A4
+Inner product checksum u =         6AF61ED5
+Inner product checksum mr1 =         3FD1D7F4
+Inner product checksum mr2 =         373D2894
+Inner product checksum mr3 =         354A0F92
+Inner product checksum mr4 =         36C033B4
 Inner product checksum mr5 =                0
 Inner product checksum mr6 =                0

rose-stem/site/meto/kgos/lfric_atm/ex1a/checksum_lfric_atm_clim_gal9_1T-C12_ex1a_cce_fast-debug-32bit.txt

@@ -1,9 +1,9 @@
-Inner product checksum rho =         46D65056
-Inner product checksum theta =         51925277
-Inner product checksum u =         6B2213D6
-Inner product checksum mr1 =         3FCF401D
-Inner product checksum mr2 =         3723DA1E
-Inner product checksum mr3 =         353FBE95
-Inner product checksum mr4 =         369202EA
+Inner product checksum rho =         46D64EC9
+Inner product checksum theta =         51925235
+Inner product checksum u =         6B21E18C
+Inner product checksum mr1 =         3FCF590B
+Inner product checksum mr2 =         37287735
+Inner product checksum mr3 =         3538B55A
+Inner product checksum mr4 =         36B2F572
 Inner product checksum mr5 =                0
 Inner product checksum mr6 =                0

rose-stem/site/meto/kgos/lfric_atm/ex1a/checksum_lfric_atm_clim_gal9_1T-C48_MG_ex1a_cce_fast-debug-32bit.txt

@@ -1,9 +1,9 @@
-Inner product checksum rho =         48D65CA4
-Inner product checksum theta =         5399FF37
-Inner product checksum u =         6B12F9D3
-Inner product checksum mr1 =         41CC35F8
-Inner product checksum mr2 =         3964700B
-Inner product checksum mr3 =         37C885DA
-Inner product checksum mr4 =         393CC0EB
+Inner product checksum rho =         48D65C72
+Inner product checksum theta =         5399FF3A
+Inner product checksum u =         6B12FBEA
+Inner product checksum mr1 =         41CC3576
+Inner product checksum mr2 =         3967A439
+Inner product checksum mr3 =         37C304A7
+Inner product checksum mr4 =         3940CDC7
 Inner product checksum mr5 =                0
 Inner product checksum mr6 =                0

rose-stem/site/meto/kgos/lfric_atm/ex1a/checksum_lfric_atm_clim_gal9_2T-C12_ex1a_cce_fast-debug-32bit.txt

@@ -1,9 +1,9 @@
-Inner product checksum rho =         46D65029
-Inner product checksum theta =         51925282
-Inner product checksum u =         6B222646
-Inner product checksum mr1 =         3FCF441A
-Inner product checksum mr2 =         373420D6
-Inner product checksum mr3 =         353B5108
-Inner product checksum mr4 =         369534B7
+Inner product checksum rho =         46D64F18
+Inner product checksum theta =         51925206
+Inner product checksum u =         6B21EEF5
+Inner product checksum mr1 =         3FCF4050
+Inner product checksum mr2 =         37532624
+Inner product checksum mr3 =         3537ACEB
+Inner product checksum mr4 =         369CB401
 Inner product checksum mr5 =                0
 Inner product checksum mr6 =                0

rose-stem/site/meto/kgos/lfric_atm/ex1a/checksum_lfric_atm_clim_gal9_2T-C48_MG_ex1a_cce_fast-debug-32bit.txt

@@ -1,9 +1,9 @@
-Inner product checksum rho =         48D65C9E
-Inner product checksum theta =         5399FF36
-Inner product checksum u =         6B12F9E6
-Inner product checksum mr1 =         41CC34F5
-Inner product checksum mr2 =         39628562
-Inner product checksum mr3 =         37CADBE8
-Inner product checksum mr4 =         393CFC10
+Inner product checksum rho =         48D65C64
+Inner product checksum theta =         5399FF3D
+Inner product checksum u =         6B12FBE8
+Inner product checksum mr1 =         41CC35EE
+Inner product checksum mr2 =         39665FD3
+Inner product checksum mr3 =         37C5CAC2
+Inner product checksum mr4 =         3940CE5A
 Inner product checksum mr5 =                0
 Inner product checksum mr6 =                0

rose-stem/site/meto/kgos/lfric_atm/ex1a/checksum_lfric_atm_clim_gal9_4T-C48_MG_ex1a_cce_fast-debug-32bit.txt

@@ -1,9 +1,9 @@
-Inner product checksum rho =         48D65C98
-Inner product checksum theta =         5399FF37
-Inner product checksum u =         6B12FA76
-Inner product checksum mr1 =         41CC32D9
-Inner product checksum mr2 =         396638BD
-Inner product checksum mr3 =         37CAADA4
-Inner product checksum mr4 =         393EB70D
+Inner product checksum rho =         48D65C6C
+Inner product checksum theta =         5399FF3A
+Inner product checksum u =         6B12FC64
+Inner product checksum mr1 =         41CC350A
+Inner product checksum mr2 =         39664DB9
+Inner product checksum mr3 =         37C0EC20
+Inner product checksum mr4 =         394121CC
 Inner product checksum mr5 =                0
 Inner product checksum mr6 =                0

rose-stem/site/meto/kgos/lfric_atm/ex1a/checksum_lfric_atm_clim_gal9_chem-C12_ex1a_cce_fast-debug-32bit.txt

@@ -1,9 +1,9 @@
-Inner product checksum rho =         46D66780
-Inner product checksum theta =         518E9690
-Inner product checksum u =         6AF50DE9
-Inner product checksum mr1 =         3FD15B81
-Inner product checksum mr2 =         37581AA6
-Inner product checksum mr3 =         355FE797
-Inner product checksum mr4 =         36D86CA0
+Inner product checksum rho =         46D6651C
+Inner product checksum theta =         518E911A
+Inner product checksum u =         6AF6B692
+Inner product checksum mr1 =         3FD1AA6E
+Inner product checksum mr2 =         374E6452
+Inner product checksum mr3 =         35374226
+Inner product checksum mr4 =         36CAD2D2
 Inner product checksum mr5 =                0
 Inner product checksum mr6 =                0

rose-stem/site/meto/kgos/lfric_atm/ex1a/checksum_lfric_atm_clim_gal9_chem_1T-C12_ex1a_cce_fast-debug-32bit.txt

@@ -1,9 +1,9 @@
-Inner product checksum rho =         46D6516E
-Inner product checksum theta =         519250DF
-Inner product checksum u =         6B22BA14
-Inner product checksum mr1 =         3FCF2C92
-Inner product checksum mr2 =         3737929A
-Inner product checksum mr3 =         35357886
-Inner product checksum mr4 =         36A9CD80
+Inner product checksum rho =         46D64E5B
+Inner product checksum theta =         51925086
+Inner product checksum u =         6B228DC3
+Inner product checksum mr1 =         3FCF67FD
+Inner product checksum mr2 =         37390858
+Inner product checksum mr3 =         3548209F
+Inner product checksum mr4 =         36B280B6
 Inner product checksum mr5 =                0
 Inner product checksum mr6 =                0

rose-stem/site/meto/kgos/lfric_atm/ex1a/checksum_lfric_atm_clim_gal9_chem_2T-C12_ex1a_cce_fast-debug-32bit.txt

@@ -1,9 +1,9 @@
-Inner product checksum rho =         46D65134
-Inner product checksum theta =         5192506E
-Inner product checksum u =         6B22D6CD
-Inner product checksum mr1 =         3FCF4DA0
-Inner product checksum mr2 =         3736B1D8
-Inner product checksum mr3 =         353E60FE
-Inner product checksum mr4 =         36A0052E
+Inner product checksum rho =         46D64DA0
+Inner product checksum theta =         519250B4
+Inner product checksum u =         6B2268C8
+Inner product checksum mr1 =         3FCF6324
+Inner product checksum mr2 =         37350051
+Inner product checksum mr3 =         353CED64
+Inner product checksum mr4 =         36A91426
 Inner product checksum mr5 =                0
 Inner product checksum mr6 =                0