Skip using fluxes provided by land component for first time step

physics/SFC_Models/Land/Noahmp/noahmpdrv.F90

@@ -420,7 +420,8 @@ end subroutine noahmpdrv_finalize
   subroutine noahmpdrv_run                                       &
 !...................................
 !  ---  inputs:
-    ( im, km, lsnowl, itime, ps, u1, v1, t1, q1, soiltyp,soilcol,&
+    ( im, km, lsnowl, itime, flag_init, ps, u1, v1, t1, q1,      &
+      soiltyp,soilcol,                                           &
       vegtype, sigmaf, dlwflx, dswsfc, snet, delt, tg3, cm, ch,  &
       prsl1, prslk1, prslki, prsik1, zf,pblh, dry, wind, slopetyp,&
       shdmin, shdmax, snoalb, sfalb, flag_iter,con_g,            &
@@ -526,6 +527,7 @@ subroutine noahmpdrv_run                                       &
   integer                                , intent(in)    :: km         ! vertical soil layer dimension
   integer                                , intent(in)    :: lsnowl     ! lower bound for snow level arrays
   integer                                , intent(in)    :: itime      ! NOT USED
+  logical                                , intent(in)    :: flag_init  ! flag signaling first time step
   real(kind=kind_phys), dimension(:)     , intent(in)    :: ps         ! surface pressure [Pa]
   real(kind=kind_phys), dimension(:)     , intent(in)    :: u1         ! u-component of wind [m/s]
   real(kind=kind_phys), dimension(:)     , intent(in)    :: v1         ! u-component of wind [m/s]
@@ -986,7 +988,7 @@ subroutine noahmpdrv_run                                       &
 !
 !  --- Just return if external land component is activated for two-way interaction
 !
-  if (cpllnd .and. cpllnd2atm) return
+  if (cpllnd .and. cpllnd2atm .and. (.not. flag_init)) return
 
   do i = 1, im
 

physics/SFC_Models/Land/Noahmp/noahmpdrv.meta

@@ -356,6 +356,13 @@
   dimensions = ()
   type = integer
   intent = in
+[flag_init]
+  standard_name = flag_for_first_timestep
+  long_name = flag signaling first time step for time integration loop
+  units = flag
+  dimensions = ()
+  type = logical
+  intent = in
 [ps]
   standard_name = surface_air_pressure
   long_name = surface pressure

physics/SFC_Models/Land/sfc_land.F90

@@ -10,6 +10,7 @@
    module sfc_land
 
    use machine, only : kind_phys
+   use funcphys, only : fpvs
 
    contains
 
@@ -28,9 +29,11 @@ module sfc_land
 !! \section general General Algorithm
 !! \section detailed Detailed Algorithm
 !! @{
-   subroutine sfc_land_run(im, cpllnd, cpllnd2atm, flag_iter, dry,   &
-     sncovr1_lnd, qsurf_lnd, evap_lnd, hflx_lnd,                     &
-     ep_lnd, t2mmp_lnd, q2mp_lnd, gflux_lnd,                         &
+   subroutine sfc_land_run(im, flag_init, flag_restart,              &
+     cpllnd, cpllnd2atm, flag_iter, dry,                             &
+     t1, q1, prsl1, prslki, ps, tskin, wind, cm, ch, rd, eps, epsm1, &
+     rvrdm1, hvap, cp, sncovr1_lnd, qsurf_lnd,                       &
+     evap_lnd, hflx_lnd, ep_lnd, t2mmp_lnd, q2mp_lnd, gflux_lnd,     &
      runoff_lnd, drain_lnd, cmm_lnd, chh_lnd, zvfun_lnd,             &
      sncovr1, qsurf, evap, hflx, ep, t2mmp, q2mp,                    &
      gflux, runoff, drain, cmm, chh, zvfun,                          &
@@ -39,11 +42,28 @@ subroutine sfc_land_run(im, cpllnd, cpllnd2atm, flag_iter, dry,   &
    implicit none
 
    ! Inputs
-   integer             , intent(in)    :: im
-   logical             , intent(in)    :: cpllnd
-   logical             , intent(in)    :: cpllnd2atm
-   logical             , intent(in)    :: flag_iter(:)
-   logical             , intent(in)    :: dry(:)
+   integer             , intent(in) :: im
+   logical             , intent(in) :: flag_init
+   logical             , intent(in) :: flag_restart
+   logical             , intent(in) :: cpllnd
+   logical             , intent(in) :: cpllnd2atm
+   logical             , intent(in) :: flag_iter(:)
+   logical             , intent(in) :: dry(:)
+   real(kind=kind_phys), intent(in) :: t1(:)
+   real(kind=kind_phys), intent(in) :: q1(:)
+   real(kind=kind_phys), intent(in) :: prsl1(:)
+   real(kind=kind_phys), intent(in) :: prslki(:)
+   real(kind=kind_phys), intent(in) :: ps(:)
+   real(kind=kind_phys), intent(in) :: tskin(:)
+   real(kind=kind_phys), intent(in) :: wind(:)
+   real(kind=kind_phys), intent(in) :: cm(:)
+   real(kind=kind_phys), intent(in) :: ch(:)
+   real(kind=kind_phys), intent(in) :: rd
+   real(kind=kind_phys), intent(in) :: eps
+   real(kind=kind_phys), intent(in) :: epsm1
+   real(kind=kind_phys), intent(in) :: rvrdm1
+   real(kind=kind_phys), intent(in) :: hvap
+   real(kind=kind_phys), intent(in) :: cp
    real(kind=kind_phys), intent(in), optional :: sncovr1_lnd(:)
    real(kind=kind_phys), intent(in), optional :: qsurf_lnd(:)
    real(kind=kind_phys), intent(in), optional :: evap_lnd(:)
@@ -75,32 +95,76 @@ subroutine sfc_land_run(im, cpllnd, cpllnd2atm, flag_iter, dry,   &
    character(len=*)    , intent(out)   :: errmsg
    integer             , intent(out)   :: errflg
 
+   ! Constant parameters
+   real(kind=kind_phys), parameter :: &
+  &    one  = 1.0_kind_phys, &
+  &    zero = 0.0_kind_phys, &
+  &    qmin = 1.0e-8_kind_phys
+
    ! Locals
    integer :: i
+   real(kind=kind_phys) :: qss, rch, tem, cpinv, hvapi, elocp
+   real(kind=kind_phys), dimension(im) :: rho, q0
 
    ! Initialize CCPP error handling variables
    errmsg = ''
    errflg = 0
 
+   cpinv = one/cp
+   hvapi = one/hvap
+   elocp = hvap/cp
+
    ! Check coupling from component land to atmosphere
    if (.not. cpllnd2atm) return
 
-   ! Fill variables
-   do i = 1, im
-      sncovr1(i) = sncovr1_lnd(i)
-      qsurf(i)   = qsurf_lnd(i)
-      hflx(i)    = hflx_lnd(i)
-      evap(i)    = evap_lnd(i)
-      ep(i)      = ep_lnd(i)
-      t2mmp(i)   = t2mmp_lnd(i)
-      q2mp(i)    = q2mp_lnd(i)
-      gflux(i)   = gflux_lnd(i)
-      drain(i)   = drain_lnd(i)
-      runoff(i)  = runoff_lnd(i)
-      cmm(i)     = cmm_lnd(i)
-      chh(i)     = chh_lnd(i)
-      zvfun(i)   = zvfun_lnd(i)
-   enddo
+   ! Check if it is cold or warm run
+   if (flag_init .and. .not. flag_restart) then 
+      ! Calculate fluxes internally
+      do i = 1, im
+         if (dry(i)) then
+            q0(i) = max(q1(i), qmin)
+            rho(i) = prsl1(i)/(rd*t1(i)*(one+rvrdm1*q0(i)))
+            qss = fpvs(tskin(i))
+            qss = eps*qss/(ps(i)+epsm1*qss)
+            rch = rho(i)*cp*ch(i)*wind(i)
+            tem = ch(i)*wind(i)
+            sncovr1(i) = zero
+            qsurf(i) = qss
+            hflx(i) = rch*(tskin(i)-t1(i)*prslki(i))
+            hflx(i) = hflx(i)*(1.0/rho(i))*cpinv
+            evap(i) = elocp*rch*(qss-q0(i))
+            ep(i) = evap(i)
+            evap(i) = evap(i)*(1.0/rho(i))*hvapi
+            t2mmp(i) = tskin(i)
+            q2mp(i) = qsurf(i)
+            gflux(i) = zero
+            drain(i) = zero
+            runoff(i) = zero
+            cmm(i) = cm(i)*wind(i)
+            chh(i) = rho(i)*tem
+            zvfun(i) = one
+         end if
+      enddo
+   else
+      ! Use fluxes from land component model 
+      do i = 1, im
+         if (dry(i)) then
+            sncovr1(i) = sncovr1_lnd(i)
+            qsurf(i)   = qsurf_lnd(i)
+            hflx(i)    = hflx_lnd(i)
+            evap(i)    = evap_lnd(i)
+            ep(i)      = ep_lnd(i)
+            t2mmp(i)   = t2mmp_lnd(i)
+            q2mp(i)    = q2mp_lnd(i)
+            gflux(i)   = gflux_lnd(i)
+            drain(i)   = drain_lnd(i)
+            runoff(i)  = runoff_lnd(i)
+            cmm(i)     = cmm_lnd(i)
+            chh(i)     = chh_lnd(i)
+            zvfun(i)   = zvfun_lnd(i)
+         end if
+      enddo
+   endif
 
    end subroutine sfc_land_run
 

physics/SFC_Models/Land/sfc_land.meta

@@ -1,7 +1,7 @@
 [ccpp-table-properties]
   name = sfc_land
   type = scheme
-  dependencies = ../../hooks/machine.F
+  dependencies = ../../tools/funcphys.f90,../../hooks/machine.F
 
 ########################################################################
 [ccpp-arg-table]
@@ -14,6 +14,20 @@
   dimensions = ()
   type = integer
   intent = in
+[flag_init]
+  standard_name = flag_for_first_timestep
+  long_name = flag signaling first time step for time integration loop
+  units = flag
+  dimensions = ()
+  type = logical
+  intent = in
+[flag_restart]
+  standard_name = flag_for_restart
+  long_name = flag for restart (warmstart) or coldstart
+  units = flag
+  dimensions = ()
+  type = logical
+  intent = in
 [cpllnd]
   standard_name = flag_for_land_coupling
   long_name = flag controlling cpllnd collection (default off)
@@ -42,6 +56,126 @@
   dimensions = (horizontal_loop_extent)
   type = logical
   intent = in
+[t1]
+  standard_name = air_temperature_at_surface_adjacent_layer
+  long_name = surface layer mean temperature
+  units = K
+  dimensions = (horizontal_loop_extent)
+  type = real
+  kind = kind_phys
+  intent = in
+[q1]
+  standard_name = specific_humidity_at_surface_adjacent_layer
+  long_name = surface layer mean specific humidity
+  units = kg kg-1
+  dimensions = (horizontal_loop_extent)
+  type = real
+  kind = kind_phys
+  intent = in
+[ps]
+  standard_name = surface_air_pressure
+  long_name = surface pressure
+  units = Pa
+  dimensions = (horizontal_loop_extent)
+  type = real
+  kind = kind_phys
+  intent = in
+[prsl1]
+  standard_name = air_pressure_at_surface_adjacent_layer
+  long_name = surface layer mean pressure
+  units = Pa
+  dimensions = (horizontal_loop_extent)
+  type = real
+  kind = kind_phys
+  intent = in
+[prslki]
+  standard_name = ratio_of_exner_function_between_midlayer_and_interface_at_lowest_model_layer
+  long_name = Exner function ratio bt midlayer and interface at 1st layer
+  units = ratio
+  dimensions = (horizontal_loop_extent)
+  type = real
+  kind = kind_phys
+  intent = in
+[tskin]
+  standard_name = surface_skin_temperature_over_land
+  long_name = surface skin temperature over land
+  units = K
+  dimensions = (horizontal_loop_extent)
+  type = real
+  kind = kind_phys
+  intent = in
+[wind]
+  standard_name = wind_speed_at_lowest_model_layer
+  long_name = wind speed at lowest model level
+  units = m s-1
+  dimensions = (horizontal_loop_extent)
+  type = real
+  kind = kind_phys
+  intent = in
+[cm]
+  standard_name = surface_drag_coefficient_for_momentum_in_air_over_land
+  long_name = surface exchange coeff for momentum over land
+  units = none
+  dimensions = (horizontal_loop_extent)
+  type = real
+  kind = kind_phys
+  intent = in
+[ch]
+  standard_name = surface_drag_coefficient_for_heat_and_moisture_in_air_over_land
+  long_name = surface exchange coeff heat & moisture over land
+  units = none
+  dimensions = (horizontal_loop_extent)
+  type = real
+  kind = kind_phys
+  intent = in
+[eps]
+  standard_name = ratio_of_dry_air_to_water_vapor_gas_constants
+  long_name = rd/rv
+  units = none
+  dimensions = ()
+  type = real
+  kind = kind_phys
+  intent = in
+[epsm1]
+  standard_name = ratio_of_dry_air_to_water_vapor_gas_constants_minus_one
+  long_name = (rd/rv) - 1
+  units = none
+  dimensions = ()
+  type = real
+  kind = kind_phys
+  intent = in
+[rvrdm1]
+  standard_name = ratio_of_vapor_to_dry_air_gas_constants_minus_one
+  long_name = (rv/rd) - 1 (rv = ideal gas constant for water vapor)
+  units = none
+  dimensions = ()
+  type = real
+  kind = kind_phys
+  intent = in
+[rd]
+  standard_name = gas_constant_of_dry_air
+  long_name = ideal gas constant for dry air
+  units = J kg-1 K-1
+  dimensions = ()
+  type = real
+  kind = kind_phys
+  intent = in
+[hvap]
+  standard_name = latent_heat_of_vaporization_of_water_at_0C
+  long_name = latent heat of evaporation/sublimation
+  units = J kg-1
+  dimensions = ()
+  type = real
+  kind = kind_phys
+  intent = in
+[cp]
+  standard_name = specific_heat_of_dry_air_at_constant_pressure
+  long_name = specific heat of dry air at constant pressure
+  units = J kg-1 K-1
+  dimensions = ()
+  type = real
+  kind = kind_phys
+  intent = in
 [sncovr1_lnd]
   standard_name = surface_snow_area_fraction_over_land_from_land
   long_name = surface snow area fraction over land for coupling