Combined updates from UFS-dev PR325 and PR326

scm/src/GFS_typedefs.F90

@@ -898,6 +898,8 @@ module GFS_typedefs
     logical              :: lrseeds         !< flag to use host-provided random seeds
     integer              :: nrstreams       !< number of random number streams in host-provided random seed array
     logical              :: lextop          !< flag for using an extra top layer for radiation
+    real(kind_phys)      :: xr_con          !< Xu-Randall cloud fraction multiplicative constant
+    real(kind_phys)      :: xr_exp          !< Xu-Randall cloud fraction exponent constant
 
     ! RRTMGP
     logical              :: do_RRTMGP               !< Use RRTMGP
@@ -3570,6 +3572,8 @@ subroutine control_initialize (Model, nlunit, fn_nml, me,         &
     logical              :: lrseeds           = .false.      !< flag to use host-provided random seeds
     integer              :: nrstreams         = 2            !< number of random number streams in host-provided random seed array
     logical              :: lextop            = .false.      !< flag for using an extra top layer for radiation
+    real(kind_phys)      :: xr_con            = -999.0       !< Xu-Randall cloud fraction multiplicative constant          
+    real(kind_phys)      :: xr_exp            = -999.0       !< Xu-Randall cloud fraction exponent constant
     ! RRTMGP
     logical              :: do_RRTMGP           = .false.    !< Use RRTMGP?
     character(len=128)   :: active_gases        = ''         !< Character list of active gases used in RRTMGP
@@ -4179,7 +4183,7 @@ subroutine control_initialize (Model, nlunit, fn_nml, me,         &
                                fhswr, fhlwr, levr, nfxr, iaerclm, iflip, isol, ico2, ialb,  &
                                isot, iems, iaer, icliq_sw, iovr, ictm, isubc_sw,            &
                                isubc_lw, lcrick, lcnorm, lwhtr, swhtr,                      &
-                               nhfrad, idcor, dcorr_con,                                    &
+                               nhfrad, idcor, dcorr_con, xr_con, xr_exp,                    &
                           ! --- RRTMGP
                                do_RRTMGP, active_gases, nGases, rrtmgp_root,                &
                                lw_file_gas, lw_file_clouds, rrtmgp_nBandsLW, rrtmgp_nGptsLW,&
@@ -4823,7 +4827,6 @@ subroutine control_initialize (Model, nlunit, fn_nml, me,         &
     Model%lrseeds          = lrseeds
     Model%nrstreams        = nrstreams
     Model%lextop           = (ltp > 0)
-
     ! RRTMGP
     Model%do_RRTMGP           = do_RRTMGP
     Model%rrtmgp_nrghice      = rrtmgp_nrghice
@@ -6581,7 +6584,34 @@ subroutine control_initialize (Model, nlunit, fn_nml, me,         &
 !--- BEGIN CODE FROM GLOOPB
 !--- set up random number seed needed for RAS and old SAS and when cal_pre=.true.
 !    Model%imfdeepcnv < 0 when Model%ras = .true.
-
+
+    if (xr_con > 0.0 .and. xr_exp > 0.0) then !values have been read in from namelist, so set them to read values
+      Model%xr_con = xr_con
+      Model%xr_exp = xr_exp
+    else  ! values have not been read in from namelist and should be set according to logic in radiation_clouds.f
+      if (Model%imp_physics == Model%imp_physics_zhao_carr .or. Model%imp_physics == Model%imp_physics_mg .or. Model%imp_physics == Model%imp_physics_fer_hires) then
+        if (.not. Model%lmfshal) then
+          !calls cloud_fraction_XuRandall()
+          Model%xr_con = 2000.0
+          Model%xr_exp = 0.25
+        else
+          !calls cloud_fraction_mass_flx_1()
+          Model%xr_con = 100.0
+          Model%xr_exp = 0.49
+        endif
+      else ! specifically used when progcld_thompson_wsm6 is called in radiation_clouds.f (see logic in that routine)
+        if (.not. Model%lmfshal) then
+          !calls cloud_fraction_XuRandall()
+          Model%xr_con = 2000.0
+          Model%xr_exp = 0.25
+        else
+          !calls cloud_fraction_mass_flx_2()
+          Model%xr_con = 2000.0
+          Model%xr_exp = 0.25
+        endif
+      endif     
+    endif
+
     if (Model%imfdeepcnv <= 0 .or. Model%cal_pre ) then
       if (Model%random_clds) then
         seed0 = Model%idate(1) + Model%idate(2) + Model%idate(3) + Model%idate(4)
@@ -6943,6 +6973,8 @@ subroutine control_print(Model)
       print *, ' lrseeds           : ', Model%lrseeds
       print *, ' nrstreams         : ', Model%nrstreams
       print *, ' lextop            : ', Model%lextop
+      print *, ' xr_con            : ', Model%xr_con
+      print *, ' xr_exp            : ', Model%xr_exp
       if (Model%do_RRTMGP) then
         print *, ' rrtmgp_nrghice     : ', Model%rrtmgp_nrghice
         print *, ' do_GPsw_Glw        : ', Model%do_GPsw_Glw

scm/src/GFS_typedefs.meta

@@ -4167,6 +4167,20 @@
   units = flag
   dimensions = ()
   type = logical
+[xr_con]
+  standard_name = multiplicative_tuning_parameter_for_Xu_Randall_cloud_fraction
+  long_name = multiplicative tuning parameter for Xu Randall cloud fraction
+  units = 1
+  dimensions = ()
+  type = real
+  kind = kind_phys
+[xr_exp]
+  standard_name = exponent_tuning_parameter_for_Xu_Randall_cloud_fraction
+  long_name = exponent tuning parameter for Xu Randall cloud fraction
+  units = 1
+  dimensions = ()
+  type = real
+  kind = kind_phys
 [active_gases]
   standard_name = active_gases_used_by_RRTMGP
   long_name = active gases used by RRTMGP