Line data    Source code

       1             : module rayleigh_friction_cam
       2             : 
       3             : !---------------------------------------------------------------------------------
       4             : ! This contains the residual code required to read namelists for the
       5             : ! Rayliegh Friction scheme. All of the functional code (the init and run subroutines)
       6             : ! has been moved to ncar_ccpp code.
       7             : !
       8             : !---------------------------------------------------------------------------------
       9             : 
      10             : use shr_kind_mod,      only: r8 => shr_kind_r8
      11             : use ppgrid,            only: pver
      12             : use spmd_utils,        only: masterproc
      13             : use phys_control,      only: use_simple_phys
      14             : use cam_logfile,       only: iulog
      15             : use cam_abortutils,    only: endrun
      16             : 
      17             : implicit none
      18             : private
      19             : save
      20             :   
      21             : ! Public interfaces
      22             : public :: rayleigh_friction_readnl  ! read namelist
      23             : ! Rayleigh friction namelist parameters for use in physpkg                                                                                            
      24             : integer, public  :: rf_nl_k0 = 2           ! vertical level at which rayleigh friction term is centered                                               
      25             : real(r8), public :: rf_nl_krange = 0._r8   ! range of rayleigh friction profile                                                                       
      26             :                                            ! if 0, range is set to satisfy x=2 (see below)                                                            
      27             : real(r8), public :: rf_nl_tau0 = 0._r8     ! approximate value of decay time at model top (days)                                                      
      28             :                                            ! if 0., no rayleigh friction is applied                                                                   
      29             : 
      30             : !===============================================================================
      31             : contains
      32             : !===============================================================================
      33             : 
      34        1024 : subroutine rayleigh_friction_readnl(nlfile)
      35             : 
      36             :    use namelist_utils,  only: find_group_name
      37             :    use units,           only: getunit, freeunit
      38             :    use spmd_utils,      only: mpicom, mstrid=>masterprocid, mpi_integer, mpi_real8
      39             : 
      40             :    character(len=*), intent(in) :: nlfile  ! filepath for file containing namelist input
      41             : 
      42             :    ! Local variables
      43             :    integer :: unitn, ierr, rayk0
      44             :    real (r8) :: raykrange, raytau0
      45             :    character(len=*), parameter :: sub = 'rayleigh_friction_readnl'
      46             : 
      47             :    namelist /rayleigh_friction_nl/ rayk0, raykrange, raytau0
      48             :    !-----------------------------------------------------------------------------
      49             : 
      50           0 :    if (use_simple_phys) return
      51             : 
      52             :    ! Initialize with default values
      53        1024 :    rayk0 = rf_nl_k0
      54        1024 :    raykrange = rf_nl_krange
      55        1024 :    raytau0 = rf_nl_tau0
      56             : 
      57        1024 :    if (masterproc) then
      58           2 :       unitn = getunit()
      59           2 :       open( unitn, file=trim(nlfile), status='old' )
      60           2 :       call find_group_name(unitn, 'rayleigh_friction_nl', status=ierr)
      61           2 :       if (ierr == 0) then
      62           0 :          read(unitn, rayleigh_friction_nl, iostat=ierr)
      63           0 :          if (ierr /= 0) then
      64           0 :             call endrun(sub//': FATAL: reading namelist')
      65             :          end if
      66             :       end if
      67           2 :       close(unitn)
      68           2 :       call freeunit(unitn)
      69             :    end if
      70             : 
      71        1024 :    call mpi_bcast(rayk0, 1, mpi_integer, mstrid, mpicom, ierr)
      72        1024 :    if (ierr /= 0) call endrun(sub//": FATAL: mpi_bcast: rayk0")
      73        1024 :    call mpi_bcast(raykrange, 1, mpi_real8, mstrid, mpicom, ierr)
      74        1024 :    if (ierr /= 0) call endrun(sub//": FATAL: mpi_bcast: raykrange")
      75        1024 :    call mpi_bcast(raytau0, 1, mpi_real8, mstrid, mpicom, ierr)
      76        1024 :    if (ierr /= 0) call endrun(sub//": FATAL: mpi_bcast: raytau0")
      77             : 
      78             :    ! Set module variables
      79        1024 :    rf_nl_tau0 = raytau0
      80        1024 :    rf_nl_krange = raykrange
      81        1024 :    rf_nl_k0 = rayk0
      82             :    
      83        1024 :    if (masterproc) then
      84           2 :       if (raytau0 > 0._r8) then
      85           0 :          write (iulog,*) 'Rayleigh friction options: '
      86           0 :          write (iulog,*) '  rayk0     = ', rf_nl_k0
      87           0 :          write (iulog,*) '  raykrange = ', rf_nl_krange
      88           0 :          write (iulog,*) '  raytau0   = ', rf_nl_tau0
      89             :       else
      90           2 :          write (iulog,*) 'Rayleigh friction not enabled.'
      91             :       end if
      92             :    end if
      93             : 
      94        1024 : end subroutine rayleigh_friction_readnl
      95             : 
      96             : !=========================================================================================
      97             : 
      98             : end module rayleigh_friction_cam