pkg/exf/exf_getffields.F

c $Header: /u/gcmpack/MITgcm/pkg/exf/exf_getffields.F,v 1.7 2002/12/28 10:11:11 dimitri Exp $

#include "EXF_CPPOPTIONS.h"

      subroutine exf_GetFFields( mycurrenttime, mycurrentiter, mythid )

c     ==================================================================
c     SUBROUTINE exf_GetFFields
c     ==================================================================
c
c     o Read-in atmospheric state and/or surface fluxes from files.
c
c     o Use bulk formulae to estimate turbulent and/or radiative
c       fluxes at the surface.
c
c     NOTES:
c     ======
c
c     See EXF_CPPOPTIONS.h for a description of the various possible
c     ocean-model forcing configurations.
c
c     The bulk formulae of pkg/exf are not valid for sea-ice covered
c     oceans but they can be used in combination with a sea-ice model,
c     for example, pkg/seaice, to specify open water flux contributions.
c
c     ==================================================================
c
c       The calculation of the bulk surface fluxes has been adapted from
c       the NCOM model which uses the formulae given in Large and Pond
c       (1981 & 1982 )
c
c
c       Header taken from NCOM version: ncom1.4.1
c       -----------------------------------------
c
c       Following procedures and coefficients in Large and Pond
c       (1981 ; 1982)
c
c       Output: Bulk estimates of the turbulent surface fluxes.
c       -------
c
c       hs  - sensible heat flux  (W/m^2), into ocean
c       hl  - latent   heat flux  (W/m^2), into ocean
c
c       Input:
c       ------
c
c       us  - mean wind speed (m/s)     at height hu (m)
c       th  - mean air temperature (K)  at height ht (m)
c       qh  - mean air humidity (kg/kg) at height hq (m)
c       sst - sea surface temperature (K)
c       tk0 - Kelvin temperature at 0 Celsius (K)
c
c       Assume 1) a neutral 10m drag coefficient =
c
c                 cdn = .0027/u10 + .000142 + .0000764 u10
c
c              2) a neutral 10m stanton number =
c
c                 ctn = .0327 sqrt(cdn), unstable
c                 ctn = .0180 sqrt(cdn), stable
c
c              3) a neutral 10m dalton number =
c
c                 cen = .0346 sqrt(cdn)
c
c              4) the saturation humidity of air at
c
c                 t(k) = exf_BulkqSat(t)  (kg/m^3)
c
c       Note:  1) here, tstar = <wt>/u*, and qstar = <wq>/u*.
c              2) wind speeds should all be above a minimum speed,
c                 say 0.5 m/s.
c              3) with optional iteration loop, niter=3, should suffice.
c              4) this version is for analyses inputs with hu = 10m and
c                 ht = hq.
c              5) sst enters in Celsius.
c
c     ==================================================================
c
c       started: Christian Eckert eckert@mit.edu 27-Aug-1999
c
c       changed: Christian Eckert eckert@mit.edu 14-Jan-2000
c              - restructured the original version in order to have a
c                better interface to the MITgcmUV.
c
c              Christian Eckert eckert@mit.edu  12-Feb-2000
c              - Changed Routine names (package prefix: exf_)
c
c              Patrick Heimbach, heimbach@mit.edu  04-May-2000
c              - changed the handling of precip and sflux with respect
c                to CPP options ALLOW_BULKFORMULAE and ALLOW_ATM_TEMP
c              - included some CPP flags ALLOW_BULKFORMULAE to make
c                sure ALLOW_ATM_TEMP, ALLOW_ATM_WIND are used only in
c                conjunction with defined ALLOW_BULKFORMULAE
c              - statement functions discarded
c
c              Ralf.Giering@FastOpt.de 25-Mai-2000
c              - total rewrite using new subroutines
c
c              Detlef Stammer: include river run-off. Nov. 21, 2001
c
c              heimbach@mit.edu, 10-Jan-2002
c              - changes to enable field swapping
c
c       mods for pkg/seaice: menemenlis@jpl.nasa.gov 20-Dec-2002
c
c     ==================================================================
c     SUBROUTINE exf_GetFFields
c     ==================================================================

      implicit none

c     == global variables ==

#include "EEPARAMS.h"
#include "SIZE.h"
#include "PARAMS.h"
#include "DYNVARS.h"
#include "GRID.h"

#include "exf_fields.h"
#include "exf_constants.h"

#ifdef ALLOW_AUTODIFF_TAMC
#include "tamc.h"
#endif

c     == routine arguments ==

      integer mythid
      integer mycurrentiter
      _RL     mycurrenttime

c     == local variables ==

      integer bi,bj
      integer i,j,k

#ifdef ALLOW_BULKFORMULAE

#ifdef ALLOW_ATM_TEMP
      integer iter
      _RL     aln
      _RL     delq
      _RL     deltap
      _RL     hqol
      _RL     htol
      _RL     huol
      _RL     psimh
      _RL     psixh
      _RL     qstar
      _RL     rd
      _RL     re
      _RL     rdn
      _RL     rh
      _RL     ssttmp
      _RL     ssq
      _RL     stable
      _RL     tstar
      _RL     t0
      _RL     ustar
      _RL     uzn
      _RL     shn
      _RL     xsq
      _RL     x
      _RL     tau
#ifdef ALLOW_AUTODIFF_TAMC
      integer ikey_1
      integer ikey_2
#endif
#endif /* ALLOW_ATM_TEMP */

      _RL     ustmp
      _RL     us
      _RL     cw
      _RL     sw
      _RL     sh
      _RL     hs(1-olx:snx+olx,1-oly:sny+oly,nsx,nsy)
      _RL     hl(1-olx:snx+olx,1-oly:sny+oly,nsx,nsy)
      _RL     hfl

#endif /* ALLOW_BULKFORMULAE */

c     == external functions ==

      integer  ilnblnk
      external ilnblnk

#ifdef ALLOW_BULKFORMULAE
      _RL       exf_BulkqSat
      external  exf_BulkqSat
      _RL       exf_BulkCdn
      external  exf_BulkCdn
      _RL       exf_BulkRhn
      external  exf_BulkRhn
#endif /* ALLOW_BULKFORMULAE */

#ifndef ALLOW_ATM_WIND
      _RL       TMP1
      _RL       TMP2
      _RL       TMP3
      _RL       TMP4
      _RL       TMP5
#endif

c     == end of interface ==

#ifdef ALLOW_BULKFORMULAE
cph   This statement cannot be a PARAMETER statement in the header,
cph   but must come here; it's not fortran77 standard
      aln = log(ht/zref)
#endif

c--   read forcing fields from files and temporal interpolation

#ifdef ALLOW_ATM_WIND

c     Zonal wind.
      call exf_set_uwind  ( mycurrenttime, mycurrentiter, mythid )

c     Meridional wind.
      call exf_set_vwind  ( mycurrenttime, mycurrentiter, mythid )

#ifdef ALLOW_UWIND_CONTROL
      call ctrl_getuwind  ( mycurrenttime, mycurrentiter, mythid )
#endif

#ifdef ALLOW_VWIND_CONTROL
      call ctrl_getvwind  ( mycurrenttime, mycurrentiter, mythid )
#endif

#else  /* ifndef ALLOW_ATM_WIND */

c     Zonal wind stress.
      call exf_set_ustress( mycurrenttime, mycurrentiter, mythid )

c     Meridional wind stress.
      call exf_set_vstress( mycurrenttime, mycurrentiter, mythid )

#endif /* ifndef ALLOW_ATM_WIND */

#ifdef ALLOW_ATM_TEMP

c     Atmospheric temperature.
      call exf_set_atemp  ( mycurrenttime, mycurrentiter, mythid )

c     Atmospheric humidity.
      call exf_set_aqh    ( mycurrenttime, mycurrentiter, mythid )

c     Net long wave radiative flux.
      call exf_set_lwflux ( mycurrenttime, mycurrentiter, mythid )

c     Precipitation.
      call exf_set_precip ( mycurrenttime, mycurrentiter, mythid )

#ifdef ALLOW_ATEMP_CONTROL
      call ctrl_getatemp  ( mycurrenttime, mycurrentiter, mythid )
#endif

#ifdef ALLOW_AQH_CONTROL
      call ctrl_getaqh    ( mycurrenttime, mycurrentiter, mythid )
#endif

#else  /* ifndef ALLOW_ATM_TEMP */

c     Atmospheric heat flux.
      call exf_set_hflux  ( mycurrenttime, mycurrentiter, mythid )

c     Salt flux.
      call exf_set_sflux  ( mycurrenttime, mycurrentiter, mythid )

#endif /* ifndef ALLOW_ATM_TEMP */

#if defined(ALLOW_ATM_TEMP) || defined(SHORTWAVE_HEATING)
c     Net short wave radiative flux.
      call exf_set_swflux ( mycurrenttime, mycurrentiter, mythid )
#endif

#ifdef EXF_READ_EVAP
c     Evaporation
      call exf_set_evap   ( mycurrenttime, mycurrentiter, mythid )
#endif

#ifdef ALLOW_DOWNWARD_RADIATION

c     Downward shortwave radiation.
      call exf_set_swdown ( mycurrenttime, mycurrentiter, mythid )

c     Downward longwave radiation.
      call exf_set_lwdown ( mycurrenttime, mycurrentiter, mythid )

#endif

c--   Use atmospheric state to compute surface fluxes.

c     Loop over tiles.
#ifdef ALLOW_AUTODIFF_TAMC
C--   HPF directive to help TAMC
CHPF$ INDEPENDENT
#endif
      do bj = mybylo(mythid),mybyhi(mythid)
#ifdef ALLOW_AUTODIFF_TAMC
C--    HPF directive to help TAMC
CHPF$  INDEPENDENT
#endif
        do bi = mybxlo(mythid),mybxhi(mythid)

          k = 1

cdm? can olx, oly be eliminated?
          do j = 1-oly,sny+oly
            do i = 1-olx,snx+olx

#ifdef ALLOW_BULKFORMULAE

#ifdef ALLOW_AUTODIFF_TAMC
               act1 = bi - myBxLo(myThid)
               max1 = myBxHi(myThid) - myBxLo(myThid) + 1
               act2 = bj - myByLo(myThid)
               max2 = myByHi(myThid) - myByLo(myThid) + 1
               act3 = myThid - 1
               max3 = nTx*nTy
               act4 = ikey_dynamics - 1

               ikey_1 = i
     &              + sNx*(j-1)
     &              + sNx*sNy*act1
     &              + sNx*sNy*max1*act2
     &              + sNx*sNy*max1*max2*act3
     &              + sNx*sNy*max1*max2*max3*act4
#endif

#ifdef ALLOW_DOWNWARD_RADIATION
c--   Compute net longwave and shortwave radiation:
c     lwflux = Stefan-Boltzman constant * emissivity * SST - lwdown
c     swflux = - ( 1 - albedo ) * swdown
               lwflux(i,j,bi,bj) = 5.5 _d -08 *
     &              ((theta(i,j,k,bi,bj)+cen2kel)**4)
     &              - lwdown(i,j,bi,bj)
               swflux(i,j,bi,bj) = -0.9 _d 0 * swdown(i,j,bi,bj)
#endif

c--   Compute the turbulent surface fluxes.

#ifdef ALLOW_ATM_WIND
c             Wind speed and direction.
              ustmp = uwind(i,j,bi,bj)*uwind(i,j,bi,bj) +
     &                vwind(i,j,bi,bj)*vwind(i,j,bi,bj)
              if ( ustmp .ne. 0. _d 0 ) then
                us = sqrt(ustmp)
                cw = uwind(i,j,bi,bj)/us
                sw = vwind(i,j,bi,bj)/us
              else
                us = 0. _d 0
                cw = 0. _d 0
                sw = 0. _d 0
              endif
              sh = max(us,umin)
#else  /* ifndef ALLOW_ATM_WIND */
#ifdef ALLOW_ATM_TEMP

c             The variables us, sh and rdn have to be computed from
c             given wind stresses inverting relationship for neutral
c             drag coeff. cdn.
c             The inversion is based on linear and quadratic form of
c             cdn(umps); ustar can be directly computed from stress;

              ustmp = ustress(i,j,bi,bj)*ustress(i,j,bi,bj) + 
     &                vstress(i,j,bi,bj)*vstress(i,j,bi,bj)
              if ( ustmp .ne. 0. _d 0 ) then
                ustar = sqrt(ustmp/atmrho)
                cw = ustress(i,j,bi,bj)/sqrt(ustmp)
                sw = vstress(i,j,bi,bj)/sqrt(ustmp)
              else
                 ustar = 0. _d 0
                 cw    = 0. _d 0
                 sw    = 0. _d 0
              endif

              if ( ustar .eq. 0. _d 0 ) then
                us = 0. _d 0
              else if ( ustar .lt. ustofu11 ) then
                tmp1 = -cquadrag_2/cquadrag_1/2
                tmp2 = sqrt(tmp1*tmp1 + ustar*ustar/cquadrag_1)
                us   = sqrt(tmp1 + tmp2)
              else
                tmp3 = clindrag_2/clindrag_1/3
                tmp4 = ustar*ustar/clindrag_1/2 - tmp3**3
                tmp5 = sqrt(ustar*ustar/clindrag_1*
     &                      (ustar*ustar/clindrag_1/4 - tmp3**3))
                us   = (tmp4 + tmp5)**(1/3) +
     &                 tmp3**2 * (tmp4 + tmp5)**(-1/3) - tmp3
              endif

              if ( us .ne. 0 ) then
                 rdn = ustar/us
              else
                 rdn = 0. _d 0
              end if

              sh    = max(us,umin)
#endif /* ALLOW_ATM_TEMP */
#endif /* ifndef ALLOW_ATM_WIND */

#ifdef ALLOW_ATM_TEMP

c             Initial guess: z/l=0.0; hu=ht=hq=z
c             Iterations:    converge on z/l and hence the fluxes.
c             t0     : virtual temperature (K)
c             ssq    : sea surface humidity (kg/kg)
c             deltap : potential temperature diff (K)

              if ( atemp(i,j,bi,bj) .ne. 0. _d 0 ) then
                t0     = atemp(i,j,bi,bj)*
     &                   (exf_one + humid_fac*aqh(i,j,bi,bj))
                ssttmp = theta(i,j,k,bi,bj)
                ssq    = saltsat*
     &                   exf_BulkqSat(ssttmp + cen2kel)/
     &                   atmrho
                deltap = atemp(i,j,bi,bj)   + gamma_blk*ht -
     &                   ssttmp - cen2kel
                delq   = aqh(i,j,bi,bj) - ssq
                stable = exf_half + sign(exf_half, deltap)
#ifdef ALLOW_AUTODIFF_TAMC
CADJ STORE sh     = comlev1_exf_1, key = ikey_1
#endif
                rdn    = sqrt(exf_BulkCdn(sh))
                ustar  = rdn*sh
                tstar  = exf_BulkRhn(stable)*deltap 
                qstar  = cdalton*delq 

                do iter = 1,niter_bulk

#ifdef ALLOW_AUTODIFF_TAMC
                   ikey_2 = iter
     &                  + niter_bulk*(i-1)
     &                  + sNx*niter_bulk*(j-1)
     &                  + sNx*niter_bulk*sNy*act1
     &                  + sNx*niter_bulk*sNy*max1*act2
     &                  + sNx*niter_bulk*sNy*max1*max2*act3
     &                  + sNx*niter_bulk*sNy*max1*max2*max3*act4

CADJ STORE rdn    = comlev1_exf_2, key = ikey_2
CADJ STORE ustar  = comlev1_exf_2, key = ikey_2
CADJ STORE qstar  = comlev1_exf_2, key = ikey_2
CADJ STORE tstar  = comlev1_exf_2, key = ikey_2
CADJ STORE sh     = comlev1_exf_2, key = ikey_2
CADJ STORE us     = comlev1_exf_2, key = ikey_2
#endif

                  huol   = czol*(tstar/t0 +
     &                     qstar/(exf_one/humid_fac+aqh(i,j,bi,bj)))/
     &                           ustar**2
                  huol   = max(huol,zolmin)
                  stable = exf_half + sign(exf_half, huol)
                  htol   = huol*ht/hu
                  hqol   = huol*hq/hu

c                 Evaluate all stability functions assuming hq = ht.
                  xsq    = max(sqrt(abs(exf_one - 16.*huol)),exf_one)
                   x     = sqrt(xsq)
                  psimh  = -psim_fac*huol*stable +
     &                     (exf_one - stable)*
     &                     log((exf_one + x*(exf_two + x))*
     &                     (exf_one + xsq)/8.) - exf_two*atan(x) +
     &                     pi*exf_half
                  xsq    = max(sqrt(abs(exf_one - 16.*htol)),exf_one)
                  psixh  = -psim_fac*htol*stable + (exf_one - stable)*
     &                     exf_two*log((exf_one + xsq)/exf_two)

c                 Shift wind speed using old coefficient
ccc                  rd   = rdn/(exf_one + rdn/karman*
ccc     &                 (log(hu/zref) - psimh) )
                  rd   = rdn/(exf_one - rdn/karman*psimh )
                  shn  = sh*rd/rdn
                  uzn  = max(shn, umin)

c                 Update the transfer coefficients at 10 meters
c                 and neutral stability.

                  rdn = sqrt(exf_BulkCdn(uzn))

c                 Shift all coefficients to the measurement height
c                 and stability.
c                 rd = rdn/(exf_one + rdn/karman*(log(hu/zref) - psimh))
                  rd = rdn/(exf_one - rdn/karman*psimh)
                  rh = exf_BulkRhn(stable)/(exf_one +
     &                                      exf_BulkRhn(stable)/
     &                                     karman*(aln - psixh))
                  re = cdalton/(exf_one + cdalton/karman*(aln - psixh))

c                 Update ustar, tstar, qstar using updated, shifted
c                 coefficients.
                  ustar = rd*sh  
                  qstar = re*delq 
                  tstar = rh*deltap
                  tau   = atmrho*ustar**2
                  tau   = tau*us/sh

                enddo

#ifdef ALLOW_AUTODIFF_TAMC
CADJ STORE ustar  = comlev1_exf_1, key = ikey_1
CADJ STORE qstar  = comlev1_exf_1, key = ikey_1
CADJ STORE tstar  = comlev1_exf_1, key = ikey_1
CADJ STORE tau    = comlev1_exf_1, key = ikey_1
CADJ STORE cw     = comlev1_exf_1, key = ikey_1
CADJ STORE sw     = comlev1_exf_1, key = ikey_1
#endif

                hs(i,j,bi,bj)      = atmcp*tau*tstar/ustar
                hl(i,j,bi,bj)      = flamb*tau*qstar/ustar
#ifndef EXF_READ_EVAP
cdm             evap(i,j,bi,bj)    = tau*qstar/ustar
cdm !!! need to change sign and to convert from kg/m^2/s to m/s !!!
                evap(i,j,bi,bj)    = -recip_rhonil*tau*qstar/ustar
#endif
                ustress(i,j,bi,bj) = tau*cw
                vstress(i,j,bi,bj) = tau*sw
              else
                ustress(i,j,bi,bj) = 0. _d 0
                vstress(i,j,bi,bj) = 0. _d 0
                hflux  (i,j,bi,bj) = 0. _d 0
                hs(i,j,bi,bj)      = 0. _d 0
                hl(i,j,bi,bj)      = 0. _d 0
              endif

#else  /* ifndef ALLOW_ATM_TEMP */
#ifdef ALLOW_ATM_WIND
              ustress(i,j,bi,bj) = atmrho*exf_BulkCdn(sh)*us*
     &                             uwind(i,j,bi,bj)
              vstress(i,j,bi,bj) = atmrho*exf_BulkCdn(sh)*us*
     &                             vwind(i,j,bi,bj)
#endif
#endif /* ifndef ALLOW_ATM_TEMP */
            enddo
          enddo
        enddo
      enddo

c     Add all contributions.
      do bj = mybylo(mythid),mybyhi(mythid)
        do bi = mybxlo(mythid),mybxhi(mythid)
          do j = 1,sny
            do i = 1,snx
c             Net surface heat flux.
#ifdef ALLOW_ATM_TEMP
              hfl = 0. _d 0
              hfl = hfl - hs(i,j,bi,bj)
              hfl = hfl - hl(i,j,bi,bj)
              hfl = hfl + lwflux(i,j,bi,bj)
#ifndef SHORTWAVE_HEATING
              hfl = hfl + swflux(i,j,bi,bj)
#endif
c             Heat flux:
              hflux(i,j,bi,bj) = hfl
c             Salt flux from Precipitation and Evaporation.
              sflux(i,j,bi,bj) = evap(i,j,bi,bj) - precip(i,j,bi,bj)
#endif /* ALLOW_ATM_TEMP */

#endif /* ALLOW_BULKFORMULAE */

#ifdef ALLOW_RUNOFF
              sflux(i,j,bi,bj) = sflux(i,j,bi,bj) - runoff(i,j,bi,bj)
#endif

              hflux(i,j,bi,bj) = hflux(i,j,bi,bj)*maskc(i,j,1,bi,bj)
              sflux(i,j,bi,bj) = sflux(i,j,bi,bj)*maskc(i,j,1,bi,bj)

            enddo
          enddo
        enddo
      enddo

c     Update the tile edges.
      _EXCH_XY_R8(hflux,   mythid)
      _EXCH_XY_R8(sflux,   mythid)
c      _EXCH_XY_R8(ustress, mythid)
c      _EXCH_XY_R8(vstress, mythid)
       CALL EXCH_UV_XY_RS(ustress, vstress, .TRUE., myThid)

#ifdef SHORTWAVE_HEATING
      _EXCH_XY_R8(swflux, mythid)
#endif

      end
1	dimitri	1.8	c $Header: /u/gcmpack/MITgcm/pkg/exf/exf_getffields.F,v 1.7 2002/12/28 10:11:11 dimitri Exp $
2	heimbach	1.1
3			#include "EXF_CPPOPTIONS.h"
4
5	heimbach	1.3	subroutine exf_GetFFields( mycurrenttime, mycurrentiter, mythid )
6	heimbach	1.1
7			c ==================================================================
8			c SUBROUTINE exf_GetFFields
9			c ==================================================================
10			c
11	dimitri	1.8	c o Read-in atmospheric state and/or surface fluxes from files.
12			c
13			c o Use bulk formulae to estimate turbulent and/or radiative
14			c fluxes at the surface.
15			c
16			c NOTES:
17			c ======
18			c
19			c See EXF_CPPOPTIONS.h for a description of the various possible
20			c ocean-model forcing configurations.
21			c
22			c The bulk formulae of pkg/exf are not valid for sea-ice covered
23			c oceans but they can be used in combination with a sea-ice model,
24			c for example, pkg/seaice, to specify open water flux contributions.
25			c
26			c ==================================================================
27	heimbach	1.1	c
28			c The calculation of the bulk surface fluxes has been adapted from
29			c the NCOM model which uses the formulae given in Large and Pond
30			c (1981 & 1982 )
31			c
32			c
33			c Header taken from NCOM version: ncom1.4.1
34			c -----------------------------------------
35			c
36			c Following procedures and coefficients in Large and Pond
37			c (1981 ; 1982)
38			c
39			c Output: Bulk estimates of the turbulent surface fluxes.
40			c -------
41			c
42			c hs - sensible heat flux (W/m^2), into ocean
43			c hl - latent heat flux (W/m^2), into ocean
44			c
45			c Input:
46			c ------
47			c
48			c us - mean wind speed (m/s) at height hu (m)
49			c th - mean air temperature (K) at height ht (m)
50			c qh - mean air humidity (kg/kg) at height hq (m)
51			c sst - sea surface temperature (K)
52			c tk0 - Kelvin temperature at 0 Celsius (K)
53			c
54			c Assume 1) a neutral 10m drag coefficient =
55			c
56			c cdn = .0027/u10 + .000142 + .0000764 u10
57			c
58			c 2) a neutral 10m stanton number =
59			c
60			c ctn = .0327 sqrt(cdn), unstable
61			c ctn = .0180 sqrt(cdn), stable
62			c
63			c 3) a neutral 10m dalton number =
64			c
65			c cen = .0346 sqrt(cdn)
66			c
67			c 4) the saturation humidity of air at
68			c
69			c t(k) = exf_BulkqSat(t) (kg/m^3)
70			c
71			c Note: 1) here, tstar = <wt>/u, and qstar = <wq>/u.
72			c 2) wind speeds should all be above a minimum speed,
73			c say 0.5 m/s.
74			c 3) with optional iteration loop, niter=3, should suffice.
75			c 4) this version is for analyses inputs with hu = 10m and
76			c ht = hq.
77			c 5) sst enters in Celsius.
78			c
79	dimitri	1.8	c ==================================================================
80	heimbach	1.1	c
81			c started: Christian Eckert eckert@mit.edu 27-Aug-1999
82			c
83			c changed: Christian Eckert eckert@mit.edu 14-Jan-2000
84			c - restructured the original version in order to have a
85			c better interface to the MITgcmUV.
86			c
87			c Christian Eckert eckert@mit.edu 12-Feb-2000
88			c - Changed Routine names (package prefix: exf_)
89			c
90			c Patrick Heimbach, heimbach@mit.edu 04-May-2000
91			c - changed the handling of precip and sflux with respect
92			c to CPP options ALLOW_BULKFORMULAE and ALLOW_ATM_TEMP
93			c - included some CPP flags ALLOW_BULKFORMULAE to make
94			c sure ALLOW_ATM_TEMP, ALLOW_ATM_WIND are used only in
95			c conjunction with defined ALLOW_BULKFORMULAE
96			c - statement functions discarded
97			c
98			c Ralf.Giering@FastOpt.de 25-Mai-2000
99	heimbach	1.4	c - total rewrite using new subroutines
100	heimbach	1.1	c
101	heimbach	1.4	c Detlef Stammer: include river run-off. Nov. 21, 2001
102			c
103			c heimbach@mit.edu, 10-Jan-2002
104			c - changes to enable field swapping
105	heimbach	1.1	c
106	dimitri	1.8	c mods for pkg/seaice: menemenlis@jpl.nasa.gov 20-Dec-2002
107	dimitri	1.7	c
108	heimbach	1.1	c ==================================================================
109			c SUBROUTINE exf_GetFFields
110			c ==================================================================
111
112			implicit none
113
114			c == global variables ==
115
116			#include "EEPARAMS.h"
117			#include "SIZE.h"
118			#include "PARAMS.h"
119			#include "DYNVARS.h"
120			#include "GRID.h"
121
122			#include "exf_fields.h"
123			#include "exf_constants.h"
124
125	heimbach	1.3	#ifdef ALLOW_AUTODIFF_TAMC
126			#include "tamc.h"
127			#endif
128
129	heimbach	1.1	c == routine arguments ==
130
131			integer mythid
132			integer mycurrentiter
133			_RL mycurrenttime
134
135			c == local variables ==
136
137			integer bi,bj
138			integer i,j,k
139
140			#ifdef ALLOW_BULKFORMULAE
141
142			#ifdef ALLOW_ATM_TEMP
143			integer iter
144			_RL aln
145			_RL delq
146			_RL deltap
147			_RL hqol
148			_RL htol
149			_RL huol
150			_RL psimh
151			_RL psixh
152			_RL qstar
153			_RL rd
154			_RL re
155			_RL rdn
156			_RL rh
157	heimbach	1.3	_RL ssttmp
158	heimbach	1.1	_RL ssq
159			_RL stable
160			_RL tstar
161			_RL t0
162			_RL ustar
163			_RL uzn
164	heimbach	1.3	_RL shn
165	heimbach	1.1	_RL xsq
166			_RL x
167	heimbach	1.3	_RL tau
168			#ifdef ALLOW_AUTODIFF_TAMC
169			integer ikey_1
170			integer ikey_2
171			#endif
172	heimbach	1.1	#endif /* ALLOW_ATM_TEMP */
173
174	heimbach	1.3	_RL ustmp
175	heimbach	1.1	_RL us
176			_RL cw
177			_RL sw
178			_RL sh
179			_RL hs(1-olx:snx+olx,1-oly:sny+oly,nsx,nsy)
180			_RL hl(1-olx:snx+olx,1-oly:sny+oly,nsx,nsy)
181			_RL hfl
182
183			#endif /* ALLOW_BULKFORMULAE */
184
185			c == external functions ==
186
187			integer ilnblnk
188			external ilnblnk
189
190			#ifdef ALLOW_BULKFORMULAE
191			_RL exf_BulkqSat
192			external exf_BulkqSat
193			_RL exf_BulkCdn
194			external exf_BulkCdn
195			_RL exf_BulkRhn
196			external exf_BulkRhn
197			#endif /* ALLOW_BULKFORMULAE */
198	cheisey	1.6
199			#ifndef ALLOW_ATM_WIND
200			_RL TMP1
201			_RL TMP2
202			_RL TMP3
203			_RL TMP4
204			_RL TMP5
205			#endif
206	heimbach	1.1
207			c == end of interface ==
208
209			#ifdef ALLOW_BULKFORMULAE
210	heimbach	1.4	cph This statement cannot be a PARAMETER statement in the header,
211			cph but must come here; it's not fortran77 standard
212	heimbach	1.3	aln = log(ht/zref)
213			#endif
214
215	dimitri	1.8	c-- read forcing fields from files and temporal interpolation
216
217			#ifdef ALLOW_ATM_WIND
218
219			c Zonal wind.
220			call exf_set_uwind ( mycurrenttime, mycurrentiter, mythid )
221
222			c Meridional wind.
223			call exf_set_vwind ( mycurrenttime, mycurrentiter, mythid )
224
225			#ifdef ALLOW_UWIND_CONTROL
226			call ctrl_getuwind ( mycurrenttime, mycurrentiter, mythid )
227			#endif
228
229			#ifdef ALLOW_VWIND_CONTROL
230			call ctrl_getvwind ( mycurrenttime, mycurrentiter, mythid )
231			#endif
232
233			#else /* ifndef ALLOW_ATM_WIND */
234
235			c Zonal wind stress.
236			call exf_set_ustress( mycurrenttime, mycurrentiter, mythid )
237
238			c Meridional wind stress.
239			call exf_set_vstress( mycurrenttime, mycurrentiter, mythid )
240
241			#endif /* ifndef ALLOW_ATM_WIND */
242
243	heimbach	1.1	#ifdef ALLOW_ATM_TEMP
244	dimitri	1.8
245	heimbach	1.1	c Atmospheric temperature.
246	dimitri	1.8	call exf_set_atemp ( mycurrenttime, mycurrentiter, mythid )
247	heimbach	1.1
248			c Atmospheric humidity.
249	dimitri	1.8	call exf_set_aqh ( mycurrenttime, mycurrentiter, mythid )
250	heimbach	1.1
251			c Net long wave radiative flux.
252	dimitri	1.8	call exf_set_lwflux ( mycurrenttime, mycurrentiter, mythid )
253	heimbach	1.1
254			c Precipitation.
255	dimitri	1.8	call exf_set_precip ( mycurrenttime, mycurrentiter, mythid )
256	heimbach	1.1
257	heimbach	1.3	#ifdef ALLOW_ATEMP_CONTROL
258	dimitri	1.8	call ctrl_getatemp ( mycurrenttime, mycurrentiter, mythid )
259	heimbach	1.3	#endif
260
261			#ifdef ALLOW_AQH_CONTROL
262	dimitri	1.8	call ctrl_getaqh ( mycurrenttime, mycurrentiter, mythid )
263	heimbach	1.3	#endif
264	heimbach	1.1
265	dimitri	1.8	#else /* ifndef ALLOW_ATM_TEMP */
266	heimbach	1.1
267			c Atmospheric heat flux.
268	dimitri	1.8	call exf_set_hflux ( mycurrenttime, mycurrentiter, mythid )
269	heimbach	1.1
270			c Salt flux.
271	dimitri	1.8	call exf_set_sflux ( mycurrenttime, mycurrentiter, mythid )
272
273			#endif /* ifndef ALLOW_ATM_TEMP */
274	heimbach	1.1
275	dimitri	1.8	#if defined(ALLOW_ATM_TEMP) \|\| defined(SHORTWAVE_HEATING)
276	heimbach	1.1	c Net short wave radiative flux.
277	dimitri	1.8	call exf_set_swflux ( mycurrenttime, mycurrentiter, mythid )
278	heimbach	1.3	#endif
279
280	dimitri	1.8	#ifdef EXF_READ_EVAP
281			c Evaporation
282			call exf_set_evap ( mycurrenttime, mycurrentiter, mythid )
283	heimbach	1.3	#endif
284	heimbach	1.1
285	dimitri	1.8	#ifdef ALLOW_DOWNWARD_RADIATION
286	heimbach	1.1
287	dimitri	1.8	c Downward shortwave radiation.
288			call exf_set_swdown ( mycurrenttime, mycurrentiter, mythid )
289	heimbach	1.1
290	dimitri	1.8	c Downward longwave radiation.
291			call exf_set_lwdown ( mycurrenttime, mycurrentiter, mythid )
292	heimbach	1.1
293	heimbach	1.3	#endif
294	heimbach	1.1
295	dimitri	1.8	c-- Use atmospheric state to compute surface fluxes.
296	dimitri	1.7
297	heimbach	1.1	c Loop over tiles.
298	heimbach	1.3	#ifdef ALLOW_AUTODIFF_TAMC
299			C-- HPF directive to help TAMC
300			CHPF$ INDEPENDENT
301	dimitri	1.8	#endif
302	heimbach	1.1	do bj = mybylo(mythid),mybyhi(mythid)
303	heimbach	1.3	#ifdef ALLOW_AUTODIFF_TAMC
304			C-- HPF directive to help TAMC
305			CHPF$ INDEPENDENT
306			#endif
307	heimbach	1.1	do bi = mybxlo(mythid),mybxhi(mythid)
308	heimbach	1.3
309	heimbach	1.1	k = 1
310
311	dimitri	1.8	cdm? can olx, oly be eliminated?
312	heimbach	1.1	do j = 1-oly,sny+oly
313			do i = 1-olx,snx+olx
314
315			#ifdef ALLOW_BULKFORMULAE
316
317	heimbach	1.3	#ifdef ALLOW_AUTODIFF_TAMC
318			act1 = bi - myBxLo(myThid)
319			max1 = myBxHi(myThid) - myBxLo(myThid) + 1
320			act2 = bj - myByLo(myThid)
321			max2 = myByHi(myThid) - myByLo(myThid) + 1
322			act3 = myThid - 1
323			max3 = nTx*nTy
324			act4 = ikey_dynamics - 1
325
326			ikey_1 = i
327			& + sNx*(j-1)
328			& + sNxsNyact1
329			& + sNxsNymax1*act2
330			& + sNxsNymax1max2act3
331			& + sNxsNymax1max2max3*act4
332			#endif
333
334	dimitri	1.8	#ifdef ALLOW_DOWNWARD_RADIATION
335			c-- Compute net longwave and shortwave radiation:
336			c lwflux = Stefan-Boltzman constant * emissivity * SST - lwdown
337			c swflux = - ( 1 - albedo ) * swdown
338			lwflux(i,j,bi,bj) = 5.5 _d -08 *
339			& ((theta(i,j,k,bi,bj)+cen2kel)**4)
340			& - lwdown(i,j,bi,bj)
341			swflux(i,j,bi,bj) = -0.9 _d 0 * swdown(i,j,bi,bj)
342			#endif
343
344			c-- Compute the turbulent surface fluxes.
345	heimbach	1.1
346			#ifdef ALLOW_ATM_WIND
347			c Wind speed and direction.
348	heimbach	1.3	ustmp = uwind(i,j,bi,bj)*uwind(i,j,bi,bj) +
349			& vwind(i,j,bi,bj)*vwind(i,j,bi,bj)
350			if ( ustmp .ne. 0. _d 0 ) then
351			us = sqrt(ustmp)
352	heimbach	1.1	cw = uwind(i,j,bi,bj)/us
353			sw = vwind(i,j,bi,bj)/us
354			else
355	heimbach	1.3	us = 0. _d 0
356	heimbach	1.1	cw = 0. _d 0
357			sw = 0. _d 0
358			endif
359			sh = max(us,umin)
360	dimitri	1.8	#else /* ifndef ALLOW_ATM_WIND */
361	heimbach	1.1	#ifdef ALLOW_ATM_TEMP
362
363	heimbach	1.3	c The variables us, sh and rdn have to be computed from
364			c given wind stresses inverting relationship for neutral
365			c drag coeff. cdn.
366	heimbach	1.1	c The inversion is based on linear and quadratic form of
367			c cdn(umps); ustar can be directly computed from stress;
368
369	heimbach	1.3	ustmp = ustress(i,j,bi,bj)*ustress(i,j,bi,bj) +
370			& vstress(i,j,bi,bj)*vstress(i,j,bi,bj)
371			if ( ustmp .ne. 0. _d 0 ) then
372			ustar = sqrt(ustmp/atmrho)
373			cw = ustress(i,j,bi,bj)/sqrt(ustmp)
374			sw = vstress(i,j,bi,bj)/sqrt(ustmp)
375			else
376			ustar = 0. _d 0
377			cw = 0. _d 0
378			sw = 0. _d 0
379			endif
380	heimbach	1.1
381			if ( ustar .eq. 0. _d 0 ) then
382			us = 0. _d 0
383			else if ( ustar .lt. ustofu11 ) then
384			tmp1 = -cquadrag_2/cquadrag_1/2
385			tmp2 = sqrt(tmp1tmp1 + ustarustar/cquadrag_1)
386			us = sqrt(tmp1 + tmp2)
387			else
388			tmp3 = clindrag_2/clindrag_1/3
389			tmp4 = ustarustar/clindrag_1/2 - tmp3*3
390			tmp5 = sqrt(ustarustar/clindrag_1
391			& (ustarustar/clindrag_1/4 - tmp3*3))
392			us = (tmp4 + tmp5)**(1/3) +
393			& tmp3*2 (tmp4 + tmp5)**(-1/3) - tmp3
394			endif
395
396			if ( us .ne. 0 ) then
397			rdn = ustar/us
398			else
399			rdn = 0. _d 0
400			end if
401
402			sh = max(us,umin)
403			#endif /* ALLOW_ATM_TEMP */
404	dimitri	1.8	#endif /* ifndef ALLOW_ATM_WIND */
405	heimbach	1.1
406			#ifdef ALLOW_ATM_TEMP
407	heimbach	1.3
408	heimbach	1.1	c Initial guess: z/l=0.0; hu=ht=hq=z
409			c Iterations: converge on z/l and hence the fluxes.
410			c t0 : virtual temperature (K)
411			c ssq : sea surface humidity (kg/kg)
412			c deltap : potential temperature diff (K)
413
414			if ( atemp(i,j,bi,bj) .ne. 0. _d 0 ) then
415			t0 = atemp(i,j,bi,bj)*
416			& (exf_one + humid_fac*aqh(i,j,bi,bj))
417	heimbach	1.3	ssttmp = theta(i,j,k,bi,bj)
418	heimbach	1.1	ssq = saltsat*
419	heimbach	1.3	& exf_BulkqSat(ssttmp + cen2kel)/
420	heimbach	1.1	& atmrho
421			deltap = atemp(i,j,bi,bj) + gamma_blk*ht -
422	heimbach	1.3	& ssttmp - cen2kel
423	heimbach	1.1	delq = aqh(i,j,bi,bj) - ssq
424			stable = exf_half + sign(exf_half, deltap)
425	heimbach	1.3	#ifdef ALLOW_AUTODIFF_TAMC
426			CADJ STORE sh = comlev1_exf_1, key = ikey_1
427			#endif
428	heimbach	1.1	rdn = sqrt(exf_BulkCdn(sh))
429			ustar = rdn*sh
430			tstar = exf_BulkRhn(stable)*deltap
431			qstar = cdalton*delq
432
433			do iter = 1,niter_bulk
434
435	heimbach	1.3	#ifdef ALLOW_AUTODIFF_TAMC
436			ikey_2 = iter
437			& + niter_bulk*(i-1)
438			& + sNxniter_bulk(j-1)
439			& + sNxniter_bulksNy*act1
440			& + sNxniter_bulksNymax1act2
441			& + sNxniter_bulksNymax1max2*act3
442			& + sNxniter_bulksNymax1max2max3act4
443
444			CADJ STORE rdn = comlev1_exf_2, key = ikey_2
445			CADJ STORE ustar = comlev1_exf_2, key = ikey_2
446			CADJ STORE qstar = comlev1_exf_2, key = ikey_2
447			CADJ STORE tstar = comlev1_exf_2, key = ikey_2
448			CADJ STORE sh = comlev1_exf_2, key = ikey_2
449			CADJ STORE us = comlev1_exf_2, key = ikey_2
450			#endif
451
452	heimbach	1.1	huol = czol*(tstar/t0 +
453			& qstar/(exf_one/humid_fac+aqh(i,j,bi,bj)))/
454			& ustar**2
455			huol = max(huol,zolmin)
456			stable = exf_half + sign(exf_half, huol)
457			htol = huol*ht/hu
458			hqol = huol*hq/hu
459
460			c Evaluate all stability functions assuming hq = ht.
461			xsq = max(sqrt(abs(exf_one - 16.*huol)),exf_one)
462			x = sqrt(xsq)
463			psimh = -psim_fachuolstable +
464			& (exf_one - stable)*
465			& log((exf_one + x(exf_two + x))
466			& (exf_one + xsq)/8.) - exf_two*atan(x) +
467			& pi*exf_half
468			xsq = max(sqrt(abs(exf_one - 16.*htol)),exf_one)
469			psixh = -psim_fachtolstable + (exf_one - stable)*
470			& exf_two*log((exf_one + xsq)/exf_two)
471
472			c Shift wind speed using old coefficient
473	heimbach	1.3	ccc rd = rdn/(exf_one + rdn/karman*
474			ccc & (log(hu/zref) - psimh) )
475	heimbach	1.1	rd = rdn/(exf_one - rdn/karman*psimh )
476	heimbach	1.3	shn = sh*rd/rdn
477			uzn = max(shn, umin)
478	heimbach	1.1
479			c Update the transfer coefficients at 10 meters
480			c and neutral stability.
481	heimbach	1.3
482	heimbach	1.1	rdn = sqrt(exf_BulkCdn(uzn))
483
484			c Shift all coefficients to the measurement height
485			c and stability.
486			c rd = rdn/(exf_one + rdn/karman*(log(hu/zref) - psimh))
487			rd = rdn/(exf_one - rdn/karman*psimh)
488			rh = exf_BulkRhn(stable)/(exf_one +
489			& exf_BulkRhn(stable)/
490			& karman*(aln - psixh))
491			re = cdalton/(exf_one + cdalton/karman*(aln - psixh))
492
493			c Update ustar, tstar, qstar using updated, shifted
494			c coefficients.
495			ustar = rd*sh
496			qstar = re*delq
497			tstar = rh*deltap
498	heimbach	1.3	tau = atmrhoustar*2
499			tau = tau*us/sh
500	heimbach	1.1
501			enddo
502
503	heimbach	1.3	#ifdef ALLOW_AUTODIFF_TAMC
504			CADJ STORE ustar = comlev1_exf_1, key = ikey_1
505			CADJ STORE qstar = comlev1_exf_1, key = ikey_1
506			CADJ STORE tstar = comlev1_exf_1, key = ikey_1
507			CADJ STORE tau = comlev1_exf_1, key = ikey_1
508			CADJ STORE cw = comlev1_exf_1, key = ikey_1
509			CADJ STORE sw = comlev1_exf_1, key = ikey_1
510			#endif
511
512	heimbach	1.1	hs(i,j,bi,bj) = atmcptautstar/ustar
513			hl(i,j,bi,bj) = flambtauqstar/ustar
514	dimitri	1.7	#ifndef EXF_READ_EVAP
515	dimitri	1.8	cdm evap(i,j,bi,bj) = tau*qstar/ustar
516			cdm !!! need to change sign and to convert from kg/m^2/s to m/s !!!
517			evap(i,j,bi,bj) = -recip_rhoniltauqstar/ustar
518			#endif
519	heimbach	1.1	ustress(i,j,bi,bj) = tau*cw
520			vstress(i,j,bi,bj) = tau*sw
521			else
522			ustress(i,j,bi,bj) = 0. _d 0
523			vstress(i,j,bi,bj) = 0. _d 0
524			hflux (i,j,bi,bj) = 0. _d 0
525			hs(i,j,bi,bj) = 0. _d 0
526			hl(i,j,bi,bj) = 0. _d 0
527			endif
528
529	dimitri	1.8	#else /* ifndef ALLOW_ATM_TEMP */
530	heimbach	1.1	#ifdef ALLOW_ATM_WIND
531			ustress(i,j,bi,bj) = atmrhoexf_BulkCdn(sh)us*
532			& uwind(i,j,bi,bj)
533			vstress(i,j,bi,bj) = atmrhoexf_BulkCdn(sh)us*
534			& vwind(i,j,bi,bj)
535	dimitri	1.8	#endif
536			#endif /* ifndef ALLOW_ATM_TEMP */
537	heimbach	1.1	enddo
538			enddo
539			enddo
540			enddo
541
542			c Add all contributions.
543			do bj = mybylo(mythid),mybyhi(mythid)
544			do bi = mybxlo(mythid),mybxhi(mythid)
545			do j = 1,sny
546			do i = 1,snx
547			c Net surface heat flux.
548			#ifdef ALLOW_ATM_TEMP
549			hfl = 0. _d 0
550			hfl = hfl - hs(i,j,bi,bj)
551			hfl = hfl - hl(i,j,bi,bj)
552			hfl = hfl + lwflux(i,j,bi,bj)
553	dimitri	1.8	#ifndef SHORTWAVE_HEATING
554	heimbach	1.1	hfl = hfl + swflux(i,j,bi,bj)
555	dimitri	1.8	#endif
556	heimbach	1.1	c Heat flux:
557	dimitri	1.8	hflux(i,j,bi,bj) = hfl
558	heimbach	1.1	c Salt flux from Precipitation and Evaporation.
559	dimitri	1.8	sflux(i,j,bi,bj) = evap(i,j,bi,bj) - precip(i,j,bi,bj)
560	heimbach	1.1	#endif /* ALLOW_ATM_TEMP */
561
562			#endif /* ALLOW_BULKFORMULAE */
563	heimbach	1.4
564			#ifdef ALLOW_RUNOFF
565	dimitri	1.8	sflux(i,j,bi,bj) = sflux(i,j,bi,bj) - runoff(i,j,bi,bj)
566			#endif
567
568			hflux(i,j,bi,bj) = hflux(i,j,bi,bj)*maskc(i,j,1,bi,bj)
569			sflux(i,j,bi,bj) = sflux(i,j,bi,bj)*maskc(i,j,1,bi,bj)
570	heimbach	1.4
571	heimbach	1.1	enddo
572			enddo
573			enddo
574			enddo
575	dimitri	1.7
576	heimbach	1.1	c Update the tile edges.
577			_EXCH_XY_R8(hflux, mythid)
578			_EXCH_XY_R8(sflux, mythid)
579	cheisey	1.5	c _EXCH_XY_R8(ustress, mythid)
580			c _EXCH_XY_R8(vstress, mythid)
581			CALL EXCH_UV_XY_RS(ustress, vstress, .TRUE., myThid)
582	heimbach	1.1
583	dimitri	1.8	#ifdef SHORTWAVE_HEATING
584	heimbach	1.1	_EXCH_XY_R8(swflux, mythid)
585	dimitri	1.8	#endif
586	heimbach	1.1
587			end