C $Header: /u/gcmpack/MITgcm/pkg/bling/bling_light.F,v 1.1 2016/05/19 20:29:26 mmazloff Exp $
C $Name: $
#include "BLING_OPTIONS.h"
CBOP
subroutine BLING_LIGHT(
I mld,
U irr_inst, irr_eff,
I bi, bj, imin, imax, jmin, jmax,
I myIter, myTime, myThid )
C =================================================================
C | subroutine bling_light
C | o calculate effective light for phytoplankton growth
C | There are multiple types of light.
C | - irr_inst is the instantaneous irradiance field.
C | - irr_mix is the same, but with the irr_inst averaged throughout
C | the mixed layer. This quantity is intended to represent the
C | light to which phytoplankton subject to turbulent transport in
C | the mixed-layer would be exposed.
C | - irr_mem is a temporally smoothed field carried between
C | timesteps, to represent photoadaptation.
C | - irr_eff is the effective irradiance for photosynthesis,
C | given either by irr_inst or irr_mix, depending on model
C | options and location.
C =================================================================
implicit none
C === Global variables ===
C irr_inst :: Instantaneous irradiance
C irr_mem :: Phyto irradiance memory
#include "SIZE.h"
#include "EEPARAMS.h"
#include "PARAMS.h"
#include "FFIELDS.h"
#include "GRID.h"
#include "DYNVARS.h"
#include "BLING_VARS.h"
#include "PTRACERS_SIZE.h"
#include "PTRACERS_PARAMS.h"
#ifdef ALLOW_AUTODIFF
# include "tamc.h"
#endif
C === Routine arguments ===
C bi,bj :: tile indices
C iMin,iMax :: computation domain: 1rst index range
C jMin,jMax :: computation domain: 2nd index range
C myTime :: current time
C myIter :: current timestep
C myThid :: thread Id. number
INTEGER bi, bj, imin, imax, jmin, jmax
INTEGER myThid
INTEGER myIter
_RL myTime
C === Input ===
_RL mld (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
C === Output ===
C irr_inst :: instantaneous light
C irr_eff :: effective light for photosynthesis
_RL irr_inst (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
_RL irr_eff (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
C === Local variables ===
_RL solar, albedo
_RL dayfrac, yday, delta
_RL lat, sun1, dayhrs
_RL cosz, frac, fluxi
_RL atten
_RL irr_surf (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
#ifdef ML_MEAN_LIGHT
_RL irr_mix (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
_RL SumMLIrr
_RL tmp_ML
#endif
#ifndef READ_PAR
#ifndef USE_QSW
_RL sfac (1-OLy:sNy+OLy)
#endif
#endif
integer i,j,k
CEOP
DO k=1,Nr
DO j=jmin,jmax
DO i=imin,imax
irr_eff(i,j,k) = 0. _d 0
ENDDO
ENDDO
ENDDO
c ---------------------------------------------------------------------
c Surface insolation
#ifndef USE_EXFQSW
c From pkg/dic/dic_insol
c find light as function of date and latitude
c based on paltridge and parson
solar = 1360. _d 0 !solar constant
albedo = 0.6 _d 0 !planetary albedo
C Case where a 2-d output array is needed: for now, stop here.
IF ( usingCurvilinearGrid .OR. rotateGrid ) THEN
STOP 'ABNORMAL END: S/R INSOL: 2-D output not implemented'
ENDIF
C find day (****NOTE for year starting in winter*****)
dayfrac=mod(myTime,360. _d 0*86400. _d 0)
& /(360. _d 0*86400. _d 0) !fraction of year
yday = 2. _d 0*PI*dayfrac !convert to radians
delta = (0.006918 _d 0
& -(0.399912 _d 0*cos(yday)) !cosine zenith angle
& +(0.070257 _d 0*sin(yday)) !(paltridge+platt)
& -(0.006758 _d 0*cos(2. _d 0*yday))
& +(0.000907 _d 0*sin(2. _d 0*yday))
& -(0.002697 _d 0*cos(3. _d 0*yday))
& +(0.001480 _d 0*sin(3. _d 0*yday)) )
DO j=1-OLy,sNy+OLy
C latitude in radians
lat=YC(1,j,1,bj)*deg2rad
C latitute in radians, backed out from coriolis parameter
C (makes latitude independent of grid)
IF ( usingCartesianGrid .OR. usingCylindricalGrid )
& lat = asin( fCori(1,j,1,bj)/(2. _d 0*omega) )
sun1 = -sin(delta)/cos(delta) * sin(lat)/cos(lat)
IF (sun1.LE.-0.999 _d 0) sun1=-0.999 _d 0
IF (sun1.GE. 0.999 _d 0) sun1= 0.999 _d 0
dayhrs = abs(acos(sun1))
cosz = ( sin(delta)*sin(lat)+ !average zenith angle
& (cos(delta)*cos(lat)*sin(dayhrs)/dayhrs) )
IF (cosz.LE.5. _d -3) cosz= 5. _d -3
frac = dayhrs/PI !fraction of daylight in day
C daily average photosynthetically active solar radiation just below surface
fluxi = solar*(1. _d 0-albedo)*cosz*frac*parfrac
C convert to sfac
sfac(j) = MAX(1. _d -5,fluxi)
ENDDO !j
#endif
c ---------------------------------------------------------------------
c instantaneous light, mixed layer averaged light
DO j=jmin,jmax
DO i=imin,imax
c Photosynthetically-available radiations (PAR)
#ifdef USE_EXFQSW
irr_surf(i,j) = max(epsln,
& -parfrac*Qsw(i,j,bi,bj)*maskC(i,j,1,bi,bj))
#else
irr_surf(i,j) = sfac(j)
#endif
cav IF ( .NOT. QSW_underice ) THEN
c if using Qsw but not seaice/thsice or coupled, then
c ice fraction needs to be taken into account
cav irr_surf(i,j) = irr_surf(i,j)*(1. _d 0 - FIce(i,j,bi,bj))
cav ENDIF
#ifdef ML_MEAN_LIGHT
SumMLIrr = 0. _d 0
tmp_ML = 0. _d 0
#endif
DO k=1,Nr
IF (hFacC(i,j,k,bi,bj).gt.0) THEN
IF (k.eq.1) THEN
c Light attenuation in middle of top layer
atten = k0*drF(1)/2. _d 0*hFacC(i,j,1,bi,bj)
irr_inst(i,j,1) = irr_surf(i,j)*exp(-atten)
ELSE
c Attenuation from one more layer
atten = k0*drF(k)/2. _d 0*hFacC(i,j,k,bi,bj)
& + k0*drF(k-1)/2. _d 0*hFacC(i,j,k-1,bi,bj)
irr_inst(i,j,k) =
& irr_inst(i,j,k-1)*exp(-atten)
ENDIF
#ifdef ML_MEAN_LIGHT
c Mean irradiance in the mixed layer
IF ((-rf(k+1) .le. mld(i,j)).and.
& (-rf(k+1).lt.200. _d 0)) THEN
SumMLIrr = SumMLIrr+drF(k)*irr_inst(i,j,k)
tmp_ML = tmp_ML + drF(k)
irr_mix(i,j) = SumMLIrr/tmp_ML
ENDIF
#endif
ENDIF
ENDDO
ENDDO
ENDDO
DO k=1,Nr
DO j=jmin,jmax
DO i=imin,imax
IF (hFacC(i,j,k,bi,bj) .gt. 0. _d 0) THEN
irr_eff(i,j,k) = irr_inst(i,j,k)
#ifdef ML_MEAN_LIGHT
c Inside mixed layer, effective light is set to mean mixed layer light
IF ((-rf(k+1) .le. mld(i,j)).and.
& (-rf(k+1).lt.200. _d 0)) THEN
irr_eff(i,j,k) = irr_mix(i,j)
ENDIF
#endif
ENDIF
ENDDO
ENDDO
ENDDO
#ifdef ALLOW_DIAGNOSTICS
IF ( useDiagnostics ) THEN
CALL DIAGNOSTICS_FILL(Qsw,'BLGQSW ',0,1,1,bi,bj,myThid)
CALL DIAGNOSTICS_FILL(irr_inst,'BLGIRRIS',0,Nr,2,bi,bj,myThid)
ENDIF
#endif
RETURN
END