Line data    Source code

       1             : module orbit
       2             : 
       3             : contains
       4             : 
       5     1495368 : subroutine zenith(calday  ,clat    , clon   ,coszrs  ,ncol, dt_avg, uniform_angle    )
       6             : 
       7             : !----------------------------------------------------------------------- 
       8             : ! 
       9             : ! Purpose: 
      10             : ! Compute cosine of solar zenith angle for albedo and radiation
      11             : !   computations.
      12             : ! 
      13             : ! Method: 
      14             : ! <Describe the algorithm(s) used in the routine.> 
      15             : ! <Also include any applicable external references.> 
      16             : ! 
      17             : ! Author: J. Kiehl
      18             : ! 
      19             : !-----------------------------------------------------------------------
      20             :    use shr_kind_mod, only: r8 => shr_kind_r8
      21             :    use shr_orb_mod
      22             :    use cam_control_mod, only: lambm0, obliqr, eccen, mvelpp
      23             :    implicit none
      24             : 
      25             : !------------------------------Arguments--------------------------------
      26             : !
      27             : ! Input arguments
      28             : !
      29             :    integer, intent(in) :: ncol                 ! number of positions
      30             :    real(r8), intent(in) :: calday              ! Calendar day, including fraction
      31             :    real(r8), intent(in) :: clat(ncol)          ! Current centered latitude (radians)
      32             :    real(r8), intent(in) :: clon(ncol)          ! Centered longitude (radians)
      33             :    real(r8), intent(in), optional :: dt_avg    ! if present, time step to use for the shr_orb_cosz calculation
      34             :    real(r8), intent(in), optional :: uniform_angle    ! if present, then call coszrs with a uniform angle
      35             : 
      36             : !
      37             : ! Output arguments
      38             : !
      39             :    real(r8), intent(out) :: coszrs(ncol)       ! Cosine solar zenith angle
      40             : !
      41             : !---------------------------Local variables-----------------------------
      42             : !
      43             :    integer i         ! Position loop index
      44             :    real(r8) delta    ! Solar declination angle  in radians
      45             :    real(r8) eccf     ! Earth orbit eccentricity factor
      46             : !
      47             : !-----------------------------------------------------------------------
      48             : !
      49             :    call shr_orb_decl (calday  ,eccen     ,mvelpp  ,lambm0  ,obliqr  , &
      50     1495368 :                       delta   ,eccf      )
      51             : !
      52             : ! Compute local cosine solar zenith angle,
      53             : !
      54             : 
      55     1495368 :    if (present(uniform_angle)) then
      56           0 :       do i=1,ncol
      57           0 :          coszrs(i) = shr_orb_cosz( calday, clat(i), clon(i), delta, dt_avg, uniform_angle=uniform_angle )
      58             :       end do
      59             :    else
      60    24969168 :       do i=1,ncol
      61    24969168 :          coszrs(i) = shr_orb_cosz( calday, clat(i), clon(i), delta, dt_avg )
      62             :       end do
      63             :    end if
      64     1495368 : end subroutine zenith
      65             : end module orbit