remove Zhao-Carr cloud schemes and combine Xu-Randall cloud fraction calculation

physics/Interstitials/UFS_SCM_NEPTUNE/GFS_rrtmgp_cloud_mp.F90

@@ -5,7 +5,7 @@
 module GFS_rrtmgp_cloud_mp
   use machine,      only: kind_phys
   use radiation_tools,   only: check_error_msg
-  use module_radiation_clouds, only: progcld_thompson
+  use module_radiation_clouds, only: progcld_thompson, cld_frac_XuRandall
   use rrtmgp_lw_cloud_optics, only: &
        radliq_lwr => radliq_lwrLW, radliq_upr => radliq_uprLW,&
        radice_lwr => radice_lwrLW, radice_upr => radice_uprLW  
@@ -346,7 +346,8 @@ subroutine cloud_mp_GF(nCol, nLev, lsmask, t_lay, p_lev, p_lay, qs_lay, relhum,
          cld_cnv_frac     !< Convective cloud-fraction (1)
     ! Local
     integer :: iCol, iLay
-    real(kind_phys) :: tem1, deltaP, clwc, qc, qi
+    real(kind_phys) :: tem1, deltaP, clwc, qc, qi, play_pa
+    real(kind_phys) :: lambda = 0.50 
 
     tem1 = 1.0e5/con_g
     do iLay = 1, nLev
@@ -372,8 +373,9 @@ subroutine cloud_mp_GF(nCol, nLev, lsmask, t_lay, p_lev, p_lay, qs_lay, relhum,
              if(qi > 1.E-8) cld_cnv_reice(iCol,iLay) = max(173.45 + 2.14*(t_lay(iCol,iLay)-273.15), 20.)
 
              ! Xu-Randall (1996) cloud-fraction.
-             cld_cnv_frac(iCol,iLay) = cld_frac_XuRandall(p_lay(iCol,iLay),            &
-                  qs_lay(iCol,iLay), relhum(iCol,iLay), qc+qi, alpha0)
+             play_pa = p_lay(iCol,iLay) *0.01
+             cld_cnv_frac(iCol,iLay) = cld_frac_XuRandall(play_pa, qs_lay(iCol,iLay),        &
+                  relhum(iCol,iLay), qc+qi, alpha0, lambda, 1.0)
           endif
        enddo
     enddo
@@ -489,7 +491,8 @@ subroutine cloud_mp_SAMF(nCol, nLev, t_lay, p_lev, p_lay, qs_lay, relhum,
          cld_cnv_frac     !< Convective cloud-fraction
     ! Local
     integer :: iCol, iLay
-    real(kind_phys) :: tem0, tem1, deltaP, clwc
+    real(kind_phys) :: tem0, tem1, deltaP, clwc, play_pa
+    real(kind_phys) :: lambda = 0.50
 
     tem0 = 1.0e5/con_g
     do iLay = 1, nLev
@@ -504,8 +507,9 @@ subroutine cloud_mp_SAMF(nCol, nLev, t_lay, p_lev, p_lay, qs_lay, relhum,
              cld_cnv_reice(iCol,iLay) = reice_def
 
              ! Xu-Randall (1996) cloud-fraction.
-             cld_cnv_frac(iCol,iLay) = cld_frac_XuRandall(p_lay(iCol,iLay),              &
-               qs_lay(iCol,iLay), relhum(iCol,iLay), cnv_mixratio(iCol,iLay), alpha0)
+             play_pa = p_lay(iCol,iLay) * 0.01
+             cld_cnv_frac(iCol,iLay) = cld_frac_XuRandall(play_pa, qs_lay(iCol,iLay),  &
+               relhum(iCol,iLay), cnv_mixratio(iCol,iLay), alpha0, lambda, 1.0)
           endif
        enddo
     enddo
@@ -706,7 +710,8 @@ subroutine cloud_mp_thompson(nCol, nLev, nTracers, ncnd, i_cldliq, i_cldice, i_c
          cld_rwp              !< Cloud rain water path
 
     ! Local variables
-    real(kind_phys) :: tem1, pfac, cld_mr, deltaP, tem2
+    real(kind_phys) :: tem1, pfac, cld_mr, deltaP, tem2, play_pa
+    real(kind_phys) :: lambda = 0.50
     real(kind_phys), dimension(nCol, nLev, min(4,ncnd)) :: cld_condensate
     integer :: iCol,iLay,l
 
@@ -740,8 +745,9 @@ subroutine cloud_mp_thompson(nCol, nLev, nTracers, ncnd, i_cldliq, i_cldice, i_c
           ! Xu-Randall (1996) cloud-fraction. **Additionally, Conditioned on relative-humidity**
           cld_mr = cld_condensate(iCol,iLay,1) + cld_condensate(iCol,iLay,2) +          &
                cld_condensate(iCol,iLay,3) + cld_condensate(iCol,iLay,4)
-          cld_frac(iCol,iLay) = cld_frac_XuRandall(p_lay(iCol,iLay),                    &
-               qs_lay(iCol,iLay), relhum(iCol,iLay), cld_mr, alpha0, cond_cfrac_onRH)
+          play_pa = p_lay(iCol,iLay) * 0.01
+          cld_frac(iCol,iLay) = cld_frac_XuRandall(play_pa, qs_lay(iCol,iLay),          &
+               relhum(iCol,iLay), cld_mr, alpha0, lambda, 1.0, cond_cfrac_onRH)
        enddo
     enddo
 
@@ -769,52 +775,6 @@ subroutine cloud_mp_thompson(nCol, nLev, nTracers, ncnd, i_cldliq, i_cldice, i_c
 
   end subroutine cloud_mp_thompson
 
-!> This function computes the cloud-fraction following
-!! Xu-Randall(1996) \cite xu_and_randall_1996 
-!!
-  function cld_frac_XuRandall(p_lay, qs_lay, relhum, cld_mr, alpha, cond_cfrac_onRH)
-    implicit none
-    ! Inputs
-   logical, intent(in), optional :: &
-       cond_cfrac_onRH    ! If true, cloud-fracion set to unity when rh>99%
-
-    real(kind_phys), intent(in) :: &
-       p_lay,    & !< Pressure (Pa)
-       qs_lay,   & !< Saturation vapor-pressure (Pa)
-       relhum,   & !< Relative humidity
-       cld_mr,   & !< Total cloud mixing ratio
-       alpha       !< Scheme parameter (default=100)
-
-    ! Outputs
-    real(kind_phys) :: cld_frac_XuRandall
-
-    ! Locals
-    real(kind_phys) :: clwt, clwm, onemrh, tem1, tem2, tem3
-
-    ! Parameters
-    real(kind_phys) :: &
-       lambda = 0.50, & !
-       P      = 0.25
-
-    clwt = 1.0e-8 * (p_lay*0.001)
-    if (cld_mr > clwt) then
-       if(present(cond_cfrac_onRH) .and. relhum > 0.99) then
-          cld_frac_XuRandall = 1.
-       else
-          onemrh = max(1.e-10, 1.0 - relhum)
-          tem1   = alpha / min(max((onemrh*qs_lay)**lambda,0.0001),1.0)
-          tem2   = max(min(tem1*(cld_mr - clwt), 50.0 ), 0.0 )
-          tem3   = sqrt(sqrt(relhum)) ! This assumes "p" = 0.25. Identical, but cheaper than relhum**p
-          !
-          cld_frac_XuRandall = max( tem3*(1.0-exp(-tem2)), 0.0 )
-      endif
-    else
-       cld_frac_XuRandall = 0.0
-    endif
-
-    return
-  end function
-
   !> This routine is a wrapper to update the Thompson effective particle sizes used by the
   !! RRTMGP radiation scheme.
   subroutine cmp_reff_Thompson(nLev, nCol, i_cldliq, i_cldice, i_cldsnow, i_cldice_nc,   &