lwrad_exponential_mod Module Reference

Simple exponential scheme to calculate the longwave radiation associated with cloud. The scheme is based on the methods used in GASS intercomparison cases, e.g. DYCOMS, ISDAC. More...

Functions/Subroutines
type(component_descriptor_type) function, public	lwrad_exponential_get_descriptor ()
	Provides the descriptor back to the caller and is used in component registration. More...
subroutine	initialisation_callback (current_state)
	The initialisation callback sets up the prescribed longwave fluxes and the exponential decay factor. More...
subroutine	timestep_callback (current_state)
	Called for each column per timestep this will apply a forcing term to the aerosol fields. More...
subroutine	finalisation_callback (current_state)

Variables
integer	iql
integer	k_top
integer	x_local
integer	y_local
real(default_precision), dimension(:), allocatable	lwrad_flux_top
real(default_precision), dimension(:), allocatable	lwrad_flux_base
real(default_precision), dimension(:), allocatable	lwrad_flux
real(default_precision), dimension(:), allocatable	qc_col
real(default_precision), dimension(:), allocatable	density_factor
real(default_precision), dimension(:), allocatable	radiation_factor
real(default_precision), dimension(:,:,:), allocatable	sth_lw
real(default_precision)	longwave_exp_decay
real(default_precision)	cltop_longwave_flux
real(default_precision)	clbase_longwave_flux

Detailed Description

Simple exponential scheme to calculate the longwave radiation associated with cloud. The scheme is based on the methods used in GASS intercomparison cases, e.g. DYCOMS, ISDAC.

This scheme depends on exp_lw, lwtop_in, lwbase_in, which are set in the config file.

Function/Subroutine Documentation

finalisation_callback()

subroutine lwrad_exponential_mod::finalisation_callback

(

type(model_state_type), intent(inout), target

current_state

)

Definition at line 164 of file lwrad_exponential.F90.

 
    type(model_state_type), target, intent(inout) :: current_state
    deallocate(lwrad_flux_top,lwrad_flux_base, lwrad_flux, density_factor, radiation_factor, sth_lw)
 

Here is the caller graph for this function:

initialisation_callback()

subroutine lwrad_exponential_mod::initialisation_callback

(

type(model_state_type), intent(inout), target

current_state

)

The initialisation callback sets up the prescribed longwave fluxes and the exponential decay factor.

Parameters

current_state

The current model state

Definition at line 57 of file lwrad_exponential.F90.

    type(model_state_type), target, intent(inout) :: current_state
 
    integer :: kkp, k ! look counter
 
    
    k_top = current_state%local_grid%size(z_index) + current_state%local_grid%halo_size(z_index) * 2
    x_local = current_state%local_grid%size(x_index) + current_state%local_grid%halo_size(x_index) * 2
    y_local = current_state%local_grid%size(y_index) + current_state%local_grid%halo_size(x_index) * 2
 
    if (is_component_enabled(current_state%options_database, "socrates_couple")) then
       call log_master_log &
            (log_error, "Socrates and lwrad_exponential both enabled, switch off one in config - STOP")
    endif
    
    allocate(lwrad_flux_top(k_top))
    allocate(lwrad_flux_base(k_top))
    allocate(lwrad_flux(k_top))
    allocate(qc_col(k_top))
    allocate(density_factor(k_top))
    allocate(radiation_factor(k_top))
    ! NOTE: this may be the wrong declaration as sth_lw may need to declared on the whole domain
    allocate(sth_lw(k_top,y_local,x_local))
 
    iql=get_q_index(standard_q_names%CLOUD_LIQUID_MASS, 'lwrad_exponential')
 
    longwave_exp_decay=options_get_real(current_state%options_database, "longwave_exp_decay")
    cltop_longwave_flux=options_get_real(current_state%options_database, "cltop_longwave_flux")
    clbase_longwave_flux=options_get_real(current_state%options_database, "clbase_longwave_flux")
 
    density_factor(:) = current_state%global_grid%configuration%vertical%rhon(:)*                  &
         current_state%global_grid%configuration%vertical%dz(:)
 
    radiation_factor(2:k_top) = 1.0/(density_factor(2:k_top)*cp)
    radiation_factor(1) = radiation_factor(2)
 

Here is the caller graph for this function:

lwrad_exponential_get_descriptor()

type(component_descriptor_type) function, public lwrad_exponential_mod::lwrad_exponential_get_descriptor

Provides the descriptor back to the caller and is used in component registration.

Returns

The termination check component descriptor

Definition at line 46 of file lwrad_exponential.F90.

    lwrad_exponential_get_descriptor%name="lwrad_exponential"
    lwrad_exponential_get_descriptor%version=0.1
    lwrad_exponential_get_descriptor%initialisation=>initialisation_callback
    lwrad_exponential_get_descriptor%timestep=>timestep_callback
    lwrad_exponential_get_descriptor%finalisation=>finalisation_callback

Here is the call graph for this function:

timestep_callback()

subroutine lwrad_exponential_mod::timestep_callback

(

type(model_state_type), intent(inout), target

current_state

)

Called for each column per timestep this will apply a forcing term to the aerosol fields.

Parameters

current_state

The current model state

Definition at line 98 of file lwrad_exponential.F90.

    type(model_state_type), target, intent(inout) :: current_state
 
    integer :: k          ! Loop counter
    integer :: icol, jcol ! Shorthand column indices
 
    real(DEFAULT_PRECISION) :: dtm  ! Local timestep variable
 
    if (current_state%halo_column) return
 
    dtm = current_state%dtm*2.0
    if (current_state%field_stepping == forward_stepping) dtm=current_state%dtm! Should this be revised to scalar_stepping
 
    icol=current_state%column_local_x
    jcol=current_state%column_local_y
 
    ! set the column liquid water content
    if (current_state%field_stepping == forward_stepping) then  ! Should this be revised to scalar_stepping
       qc_col(:) = current_state%q(iql)%data(:, jcol, icol) + current_state%sq(iql)%data(:, jcol, icol)*dtm
    else
       qc_col(:)= current_state%zq(iql)%data(:, jcol, icol) + current_state%sq(iql)%data(:, jcol, icol)*dtm
 
    end if
 
    ! initialise the flux top and base to 0.0
    lwrad_flux_top(:) = 0.0
    lwrad_flux_base(:) = 0.0
 
    ! First workout cloud top cooling
    lwrad_flux_top(k_top)=cltop_longwave_flux !units Wm-2
 
    do k = k_top-1, 1, -1
       if (qc_col(k+1) > 1.e-10) then
          lwrad_flux_top(k) = lwrad_flux_top(k+1)*                                    &
               exp(-qc_col(k+1)*density_factor(k+1)*longwave_exp_decay)
       else
          lwrad_flux_top(k) = lwrad_flux_top(k+1)
       endif
    enddo
 
    ! Second workout the cloud base warming
    do k = 2, k_top
       if (qc_col(k) > 1.e-10) then
          lwrad_flux_base(k) = lwrad_flux_base(k-1)*                                  &
               exp(-qc_col(k)*density_factor(k)*longwave_exp_decay)
       else
          lwrad_flux_base(k) = lwrad_flux_base(k-1)
       endif
    enddo
 
    ! Next, sum the fluxes
    do k = 1, k_top
       lwrad_flux(k) = lwrad_flux_base(k) + lwrad_flux_top(k)
    enddo
 
    ! workout radiative heating rate, and stored on the processors local grid - is this correct??
    ! or should the declaration be on the global grid?
    do k = 2, k_top
       sth_lw(k, jcol, icol) = -(lwrad_flux(k) - lwrad_flux(k-1))*radiation_factor(k)
    enddo
 
    ! update the current_state sth
    current_state%sth%data(:, jcol, icol) = current_state%sth%data(:, jcol, icol) + sth_lw(:, jcol, icol)
 

Here is the caller graph for this function:

Variable Documentation

clbase_longwave_flux

real(default_precision) lwrad_exponential_mod::clbase_longwave_flux

Definition at line 38 of file lwrad_exponential.F90.

cltop_longwave_flux

real(default_precision) lwrad_exponential_mod::cltop_longwave_flux

Definition at line 38 of file lwrad_exponential.F90.

density_factor

real(default_precision), dimension(:), allocatable lwrad_exponential_mod::density_factor

Definition at line 31 of file lwrad_exponential.F90.

  real(DEFAULT_PRECISION), allocatable ::  density_factor(:), radiation_factor(:)

iql

integer lwrad_exponential_mod::iql

Definition at line 21 of file lwrad_exponential.F90.

  integer :: iql

k_top

integer lwrad_exponential_mod::k_top

Definition at line 23 of file lwrad_exponential.F90.

  integer :: k_top, x_local, y_local

longwave_exp_decay

real(default_precision) lwrad_exponential_mod::longwave_exp_decay

Definition at line 38 of file lwrad_exponential.F90.

  real(DEFAULT_PRECISION) :: longwave_exp_decay, cltop_longwave_flux, clbase_longwave_flux

lwrad_flux

real(default_precision), dimension(:), allocatable lwrad_exponential_mod::lwrad_flux

Definition at line 27 of file lwrad_exponential.F90.

lwrad_flux_base

real(default_precision), dimension(:), allocatable lwrad_exponential_mod::lwrad_flux_base

Definition at line 27 of file lwrad_exponential.F90.

lwrad_flux_top

real(default_precision), dimension(:), allocatable lwrad_exponential_mod::lwrad_flux_top

Definition at line 27 of file lwrad_exponential.F90.

  real(DEFAULT_PRECISION), allocatable ::  lwrad_flux_top(:), lwrad_flux_base(:), lwrad_flux(:)

qc_col

real(default_precision), dimension(:), allocatable lwrad_exponential_mod::qc_col

Definition at line 29 of file lwrad_exponential.F90.

  real(DEFAULT_PRECISION), allocatable ::  qc_col(:)

radiation_factor

real(default_precision), dimension(:), allocatable lwrad_exponential_mod::radiation_factor

Definition at line 31 of file lwrad_exponential.F90.

sth_lw

real(default_precision), dimension(:,:,:), allocatable lwrad_exponential_mod::sth_lw

Definition at line 35 of file lwrad_exponential.F90.

  real(DEFAULT_PRECISION), allocatable :: sth_lw(:,:,:)

x_local

integer lwrad_exponential_mod::x_local

Definition at line 23 of file lwrad_exponential.F90.

y_local

integer lwrad_exponential_mod::y_local

Definition at line 23 of file lwrad_exponential.F90.