Line data    Source code

       1             : 
       2             : module mo_mean_mass
       3             : 
       4             :   implicit none
       5             : 
       6             :   private
       7             :   public :: set_mean_mass, init_mean_mass
       8             : 
       9             :   integer :: id_o2, id_o, id_h, id_n
      10             : 
      11             : contains
      12             : 
      13           0 :   subroutine init_mean_mass
      14             :     use mo_chem_utls, only : get_spc_ndx
      15             : 
      16             :     implicit none
      17             : 
      18           0 :     id_o2 = get_spc_ndx('O2')
      19           0 :     id_o  = get_spc_ndx('O')
      20           0 :     id_h  = get_spc_ndx('H')
      21           0 :     id_n  = get_spc_ndx('N')
      22             : 
      23           0 :   endsubroutine init_mean_mass
      24             : 
      25           0 :   subroutine set_mean_mass( ncol, mmr, mbar )
      26             :     !-----------------------------------------------------------------
      27             :     !        ... Set the invariant densities (molecules/cm**3)
      28             :     !-----------------------------------------------------------------
      29             : 
      30             :     use shr_kind_mod,     only : r8 => shr_kind_r8
      31             :     use ppgrid,           only : pver, pcols
      32             :     use chem_mods,        only : adv_mass, gas_pcnst
      33             :     use physconst,        only : mwdry                   ! molecular weight of dry air
      34             :     use cam_abortutils,   only : endrun
      35             :     use phys_control,     only : waccmx_is               !WACCM-X runtime switch
      36             : 
      37             :     implicit none
      38             : 
      39             :     !-----------------------------------------------------------------
      40             :     !        ... Dummy arguments
      41             :     !-----------------------------------------------------------------
      42             :     integer, intent(in)   ::      ncol
      43             :     real(r8), intent(in)  ::      mmr(:,:,:)           ! species concentrations (kg/kg)
      44             :     real(r8), intent(out) ::      mbar(:,:)            ! mean mass (g/mole)
      45             : 
      46             :     !-----------------------------------------------------------------
      47             :     !        ... Local variables
      48             :     !-----------------------------------------------------------------
      49             :     integer  :: k
      50           0 :     real(r8) :: xn2(ncol)                                  ! n2 mmr
      51           0 :     real(r8) :: fn2(ncol)                                  ! n2 vmr
      52           0 :     real(r8) :: fo(ncol)                                   ! o  vmr
      53           0 :     real(r8) :: fo2(ncol)                                  ! o2 vmr
      54           0 :     real(r8) :: fh(ncol)                                   ! h vmr
      55             :     real(r8) :: ftot(ncol)                                 ! total vmr
      56             :     real(r8) :: mean_mass(ncol)                            ! wrk variable
      57             : 
      58             :     logical  :: fixed_mbar                                 ! Fixed mean mass flag
      59             : 
      60             :     !-------------------------------------------
      61             :     !  Mean mass not fixed for WACCM-X
      62             :     !-------------------------------------------
      63           0 :     if ( waccmx_is('ionosphere') .or. waccmx_is('neutral') ) then
      64             :       fixed_mbar = .false.
      65             :     else
      66             :       fixed_mbar = .true.
      67             :     endif
      68             : 
      69             :     if( fixed_mbar ) then
      70             :        !-----------------------------------------------------------------
      71             :        !        ... use CAM meam molecular weight 
      72             :        !-----------------------------------------------------------------
      73           0 :        mbar(:ncol,:pver) = mwdry  
      74             :     else
      75           0 :        if ( id_o2 > 0 .and. id_o > 0 .and. id_h > 0 .and. id_n > 0 ) then
      76             :           !-----------------------------------------------------------------
      77             :           !     ... set the mean mass
      78             :           !-----------------------------------------------------------------
      79             :           do k = 1,pver
      80           0 :              xn2(:)    = 1._r8 - (mmr(:ncol,k,id_o2) + mmr(:ncol,k,id_o) + mmr(:ncol,k,id_h))
      81           0 :              fn2(:)    = .5_r8 * xn2(:) / adv_mass(id_n)
      82             :              fo2(:)    = mmr(:ncol,k,id_o2) / adv_mass(id_o2)
      83             :              fo(:)     = mmr(:ncol,k,id_o) / adv_mass(id_o)
      84             :              fh(:)     = mmr(:ncol,k,id_h) / adv_mass(id_h)
      85             :              mbar(:ncol,k) = 1._r8 / (fn2(:) + fo2(:) + fo(:) + fh(:))
      86             :           end do
      87             :        else
      88           0 :           call endrun('set_mean_mass: not able to compute mean mass')
      89             :        endif
      90             :     endif
      91             : 
      92           0 :   end subroutine set_mean_mass
      93             : 
      94             : end module mo_mean_mass