! calculates the photosynthesis temperatures
!
! $Header: /home/ssipsl/CVSREP/ORCHIDEE/src_stomate/stomate_assimtemp.f90,v 1.7 2009/01/06 17:18:32 ssipsl Exp $
! IPSL (2006)
!  This software is governed by the CeCILL licence see ORCHIDEE/ORCHIDEE_CeCILL.LIC
!
MODULE stomate_assimtemp

  ! modules used:

  USE pft_parameters
  USE constantes 

  IMPLICIT NONE

  ! private & public routines

  PRIVATE
  PUBLIC assim_temp

CONTAINS

  SUBROUTINE assim_temp (npts, tlong_ref, t2m_month, t_photo_min, t_photo_opt, t_photo_max)

    !
    ! 0 declarations
    !

    ! 0.1 input

    ! Domain size
    INTEGER(i_std), INTENT(in)                                        :: npts
    ! "long term" 2 meter reference temperatures (K)
    REAL(r_std), DIMENSION(npts), INTENT(in)                    :: tlong_ref
    ! "monthly" 2-meter temperatures (K)
    REAL(r_std), DIMENSION(npts), INTENT(in)                    :: t2m_month

    ! 0.2 output
    ! Minimum temperature for photosynthesis (K)
    REAL(r_std), DIMENSION(npts,nvm), INTENT(out)              :: t_photo_min
    ! Optimum temperature for photosynthesis (K)
    REAL(r_std), DIMENSION(npts,nvm), INTENT(out)              :: t_photo_opt
    ! Maximum temperature for photosynthesis (K)
    REAL(r_std), DIMENSION(npts,nvm), INTENT(out)              :: t_photo_max

    ! 0.3 local
    ! "long term" 2 meter reference temperatures (deg C)
    REAL(r_std), DIMENSION(npts)                                :: tl
    ! Index
    INTEGER(i_std)                                             :: j

    ! =========================================================================

    tl(:) = tlong_ref(:) - ZeroCelsius

    DO j = 2,nvm

       !
       ! 1 normal case
       !

       t_photo_min(:,j) = tphoto_min_c(j) + tphoto_min_b(j)*tl(:) + tphoto_min_a(j)*tl(:)*tl(:) + ZeroCelsius
       t_photo_opt(:,j) = tphoto_opt_c(j) + tphoto_opt_b(j)*tl(:) + tphoto_opt_a(j)*tl(:)*tl(:) + ZeroCelsius
       t_photo_max(:,j) = tphoto_max_c(j) + tphoto_max_b(j)*tl(:) + tphoto_max_a(j)*tl(:)*tl(:) + ZeroCelsius

       !
       ! 2 If the monthly temperature is too low, we set tmax < tmin.
       !   Therefore, photosynthesis will not be possible (we need tmin < t < tmax)
       !

       WHERE ( t2m_month(:) .LT. t_photo_min(:,j) )
          t_photo_max(:,j) = t_photo_min(:,j) - min_stomate
       ENDWHERE

    ENDDO

  END SUBROUTINE assim_temp

END MODULE stomate_assimtemp