!=======================================================================
!BOP
!
! !MODULE: ice_ocean - ocean mixed layer internal to sea ice model
!
! !DESCRIPTION:
!
! Ocean mixed layer calculation (internal to sea ice model).
! Allows heat storage in ocean for uncoupled runs.
!
! !REVISION HISTORY:
! SVN:$Id: ice_ocean.F90 131 2008-05-30 16:53:40Z eclare $
!
! authors: John Weatherly, CRREL
! C.M. Bitz, UW
! Elizabeth C. Hunke, LANL
! Bruce P. Briegleb, NCAR
! William H. Lipscomb, LANL
!
! 2004: Block structure added by William Lipscomb
! 2005: Ocean-to-atmosphere fluxes added as 3D arrays, William Lipscomb
! 2006: Converted to free source form (F90) by Elizabeth Hunke
!
! !INTERFACE:
!
module ice_ocean 8,2
!
! !USES:
!
use ice_kinds_mod
use ice_constants
!
!EOP
!
implicit none
save
logical (kind=log_kind) :: &
oceanmixed_ice ! if true, use ocean mixed layer
real (kind=dbl_kind), parameter :: &
cprho = cp_ocn*rhow
!=======================================================================
contains
!=======================================================================
!BOP
!
! !ROUTINE: ocean_mixed_layer - compute SST and freeze/melt potential
!
! !DESCRIPTION:
!
! Compute the mixed layer heat balance and update the SST.
! Compute the energy available to freeze or melt ice.
! NOTE: SST changes due to fluxes through the ice are computed in
! ice_therm_vertical.
!
! !REVISION HISTORY: same as module
!
! !INTERFACE:
!
subroutine ocean_mixed_layer (dt) 2,8
!
! !USES:
!
use ice_blocks
use ice_domain
use ice_state, only: aice, uvel, vvel
use ice_flux
use ice_grid, only: tmask
use ice_atmo, only: atmo_boundary_layer, atmbndy, atmo_boundary_const
!
! !INPUT/OUTPUT PARAMETERS:
!
real (kind=dbl_kind), intent(in) :: &
dt ! time step
!
!EOP
!
real (kind=dbl_kind) :: &
TsfK , & ! surface temperature (K)
swabs ! surface absorbed shortwave heat flux (W/m^2)
real (kind=dbl_kind), parameter :: &
frzmlt_max = c1000 ! max magnitude of frzmlt (W/m^2)
integer (kind=int_kind) :: &
i, j , & ! horizontal indices
ij , & ! combined ij index
iblk , & ! block index
ilo,ihi,jlo,jhi ! beginning and end of physical domain
real (kind=dbl_kind), dimension(nx_block,ny_block) :: &
delt , & ! potential temperature difference (K)
delq , & ! specific humidity difference (kg/kg)
shcoef, & ! transfer coefficient for sensible heat
lhcoef ! transfer coefficient for latent heat
integer (kind=int_kind), save :: &
icells ! number of ocean cells
integer (kind=int_kind), dimension(nx_block*ny_block), save :: &
indxi, indxj ! compressed indices for ocean cells
type (block) :: &
this_block ! block information for current block
do iblk = 1, nblocks
!-----------------------------------------------------------------
! Identify ocean cells.
! Set fluxes to zero in land cells.
!-----------------------------------------------------------------
icells = 0
do j = 1, ny_block
do i = 1, nx_block
if (tmask(i,j,iblk)) then
icells = icells + 1
indxi(icells) = i
indxj(icells) = j
else
sst (i,j,iblk) = c0
frzmlt (i,j,iblk) = c0
flwout_ocn(i,j,iblk) = c0
fsens_ocn (i,j,iblk) = c0
flat_ocn (i,j,iblk) = c0
evap_ocn (i,j,iblk) = c0
endif
enddo ! i
enddo ! j
!-----------------------------------------------------------------
! Compute boundary layer quantities
!-----------------------------------------------------------------
if (trim(atmbndy) == 'constant') then
call atmo_boundary_const (nx_block, ny_block, &
'ice', icells, &
indxi, indxj, &
uatm (:,:,iblk), &
vatm (:,:,iblk), &
wind (:,:,iblk), &
rhoa (:,:,iblk), &
strairx_ocn(:,:,iblk), &
strairy_ocn(:,:,iblk), &
lhcoef (:,:), &
shcoef (:,:) )
else ! default
call atmo_boundary_layer (nx_block, ny_block, &
'ocn', icells, &
indxi, indxj, &
sst (:,:,iblk), &
potT (:,:,iblk), &
uatm (:,:,iblk), &
vatm (:,:,iblk), &
uvel (:,:,iblk), &
vvel (:,:,iblk), &
wind (:,:,iblk), &
zlvl (:,:,iblk), &
Qa (:,:,iblk), &
rhoa (:,:,iblk), &
strairx_ocn(:,:,iblk), &
strairy_ocn(:,:,iblk), &
Tref_ocn (:,:,iblk), &
Qref_ocn (:,:,iblk), &
delt (:,:), &
delq (:,:), &
lhcoef (:,:), &
shcoef (:,:) )
endif
!-----------------------------------------------------------------
! Ocean albedo
! For now, assume albedo = albocn in each spectral band.
!-----------------------------------------------------------------
alvdr_ocn(:,:,iblk) = albocn
alidr_ocn(:,:,iblk) = albocn
alvdf_ocn(:,:,iblk) = albocn
alidf_ocn(:,:,iblk) = albocn
!-----------------------------------------------------------------
! Compute ocean fluxes and update SST
!-----------------------------------------------------------------
!DIR$ CONCURRENT !Cray
!cdir nodep !NEC
!ocl novrec !Fujitsu
do ij = 1, icells
i = indxi(ij)
j = indxj(ij)
! shortwave radiative flux
swabs = (c1-alvdr_ocn(i,j,iblk)) * swvdr(i,j,iblk) &
+ (c1-alidr_ocn(i,j,iblk)) * swidr(i,j,iblk) &
+ (c1-alvdf_ocn(i,j,iblk)) * swvdf(i,j,iblk) &
+ (c1-alidf_ocn(i,j,iblk)) * swidf(i,j,iblk)
! ocean surface temperature in Kelvin
TsfK = sst(i,j,iblk) + Tffresh
! longwave radiative flux
flwout_ocn(i,j,iblk) = -stefan_boltzmann * TsfK**4
! downward latent and sensible heat fluxes
fsens_ocn(i,j,iblk) = shcoef(i,j) * delt(i,j)
flat_ocn (i,j,iblk) = lhcoef(i,j) * delq(i,j)
evap_ocn (i,j,iblk) = -flat_ocn(i,j,iblk) / Lvap
! Compute sst change due to exchange with atm/ice above
sst(i,j,iblk) = sst(i,j,iblk) + dt * ( &
(fsens_ocn(i,j,iblk) + flat_ocn(i,j,iblk) + flwout_ocn(i,j,iblk) &
+ flw(i,j,iblk) + swabs) * (c1-aice(i,j,iblk)) &
+ fhocn(i,j,iblk) + fswthru(i,j,iblk)) & ! these are *aice
/ (cprho*hmix(i,j,iblk))
! adjust qdp if cooling of mixed layer would occur when sst <= Tf
if (sst(i,j,iblk) <= Tf(i,j,iblk) .and. qdp(i,j,iblk) > c0) qdp(i,j,iblk) = c0
! computed T change due to exchange with deep layers:
sst(i,j,iblk) = sst(i,j,iblk) - qdp(i,j,iblk)*dt/(cprho*hmix(i,j,iblk))
! compute potential to freeze or melt ice
frzmlt(i,j,iblk) = (Tf(i,j,iblk)-sst(i,j,iblk))*cprho*hmix(i,j,iblk)/dt
frzmlt(i,j,iblk) = min(max(frzmlt(i,j,iblk),-frzmlt_max),frzmlt_max)
! if sst is below freezing, reset sst to Tf
if (sst(i,j,iblk) <= Tf(i,j,iblk)) sst(i,j,iblk) = Tf(i,j,iblk)
enddo ! ij
enddo ! iblk
end subroutine ocean_mixed_layer
!=======================================================================
end module ice_ocean
!=======================================================================