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Module rh_based_clouds_mod

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OVERVIEW

module which defines cloud locations based on model relative humidity



OTHER MODULES USED

          fms_mod
rh_clouds_mod
rad_utilities_mod
constants_mod

PUBLIC INTERFACE

rh_based_clouds_init:
rh_based_clouds_end:
rh_clouds_amt:
rh_clouds_amt defines the location, amount (cloud fraction), number and type (hi, mid, low) of clouds present on the model grid.

obtain_bulk_lw_rh:
obtain_bulk_lw_rh defines bulk longwave cloud radiative properties for the rh cloud scheme.

obtain_bulk_sw_rh:
obtain_bulk_sw_rh defines bulk shortwave cloud radiative properties for the rh cloud scheme.

cldalb:
cldalb calculates a zenith angle dependency for the cloud albedos. the cloud albedos are interpolated using data adapted from fritz (1954). the solar zenith angle is the only input required.

albcld_lw:
albcld_lw computes the lw cloud emissivities. This calculation is based on sigma and cloud thickness in the old scheme (cldht60) and sigma, cloud thickness and latitude in the new scheme (cldht93).

albcld_sw:
albcld_sw computes the cloud albedos. This calculation is based on sigma and cloud thickness in the old scheme (cldht60) and sigma, cloud thickness and latitude in the new scheme (cldht93).



PUBLIC DATA

None.


PUBLIC ROUTINES

  1. rh_based_clouds_init

    call rh_based_clouds_init 
    
    DESCRIPTION


  2. rh_based_clouds_end

    call rh_based_clouds_end 
    
    DESCRIPTION


  3. rh_clouds_amt

    call rh_clouds_amt (is, ie, js, je, press, lat, Cld_spec)
    DESCRIPTION
    rh_clouds_amt defines the location, amount (cloud fraction), number and type (hi, mid, low) of clouds present on the model grid.



    INPUT
    is    is,ie,js,je starting/ending subdomain i,j indices of data in the physics_window being integrated


       [integer]
    ie   
       [integer]
    js   
       [integer]
    je   
       [integer]
    press    press pressure at model levels (1:nlev), surface pressure is stored at index value nlev+1 [ (kg /( m s^2) ]


       [real]
    lat    lat latitude of model points [ radians ]


       [real]

    INPUT/OUTPUT
    Cld_spec    Cld_spec cld_specification_type variable containing the cloud specification input fields needed by the radiation package

    the following elements of Cld_spec are defined here:

    %cmxolw fraction of maximally overlapped clouds seen by the longwave radiation [ dimensionless ] %crndlw fraction of randomly overlapped clouds seen by the longwave radiation [ dimensionless ] %camtsw cloud fraction seen by the shortwave radiation; the sum of the maximally overlapped and randomly overlapped longwave cloud fractions [ dimensionless ] %nmxolw number of maximally overlapped longwave clouds in each grid column. %nrndlw number of randomly overlapped longwave clouds in each grid column. %ncldsw number of clouds seen by he shortwave radiation in each grid column. %hi_cld logical flag indicating the presence of high clouds in a grid box %mid_cld logical flag indicating the presence of middle clouds in a grid box %low_cld logical flag indicating the presence of low clouds in a grid box


       [cld_specification_type]

  4. obtain_bulk_lw_rh

    call obtain_bulk_lw_rh (is, ie, js, je, Cld_spec, Cldrad_props)
    DESCRIPTION
    obtain_bulk_lw_rh defines bulk longwave cloud radiative properties for the rh cloud scheme.



    INPUT
    is    is,ie,js,je starting/ending subdomain i,j indices of data in the physics_window being integrated


       [integer]
    ie   
       [integer]
    js   
       [integer]
    je   
       [integer]
    Cld_spec    Cld_spec cloud specification arrays defining the location, amount and type (hi, middle, lo) of clouds that are present, provides input to this subroutine [ cld_specification_type ]


       [cld_specification_type]

    INPUT/OUTPUT
    Cldrad_props    Cldrad_props cloud radiative properties on model grid, [ cldrad_properties_type ]

    the following components of this variable are output from this routine:

    %emrndlw longwave cloud emissivity for randomly overlapped clouds in each of the longwave frequency bands [ dimensionless ] %emmxolw longwave cloud emissivity for maximally overlapped clouds in each of the longwave frequency bands [ dimensionless ]


       [cldrad_properties_type]

  5. obtain_bulk_sw_rh

    call obtain_bulk_sw_rh (is, ie, js, je, cosz, Cld_spec, & Cldrad_props)
    DESCRIPTION
    obtain_bulk_sw_rh defines bulk shortwave cloud radiative properties for the rh cloud scheme.



    INPUT
    is    is,ie,js,je starting/ending subdomain i,j indices of data in the physics_window being integrated


       [integer]
    ie   
       [integer]
    js   
       [integer]
    je   
       [integer]
    cosz    cosz cosine of the zenith angle [ dimensionless ]


       [real]
    Cld_spec    Cld_spec cloud specification arrays defining the location, amount and type (hi, middle, lo) of clouds that are present, provides input to this subroutine [ cld_specification_type ]


       [cld_specification_type]

    INPUT/OUTPUT
    Cldrad_props    Cldrad_props cloud radiative properties on model grid, [ cldrad_properties_type ]

    the following components of this variable are output from this routine:

    %cirabsw absorptivity of clouds in the infrared frequency band [ dimensionless ] %cirrfsw reflectivity of clouds in the infrared frequency band [ dimensionless ] %cvisrfsw reflectivity of clouds in the visible frequency band [ dimensionless ]


       [cldrad_properties_type]

  6. cldalb

    call cldalb (zenith)
    DESCRIPTION
    cldalb calculates a zenith angle dependency for the cloud albedos. the cloud albedos are interpolated using data adapted from fritz (1954). the solar zenith angle is the only input required.



    INPUT
    zenith    zenith angle
       [real]

  7. albcld_lw

    call albcld_lw (hi_cloud, mid_cloud, low_cloud, & cmxolw, crndlw, emmxolw, emrndlw)
    DESCRIPTION
    albcld_lw computes the lw cloud emissivities. This calculation is based on sigma and cloud thickness in the old scheme (cldht60) and sigma, cloud thickness and latitude in the new scheme (cldht93).



    INPUT
    hi_cloud   
       [logical]
    mid_cloud   
       [logical]
    low_cloud   
       [logical]
    cmxolw   
       [real]
    crndlw   
       [real]

    INPUT/OUTPUT
    emmxolw   
       [real]
    emrndlw   
       [real]

  8. albcld_sw

    call albcld_sw (i,j, hi_cloud, mid_cloud, low_cloud, & camtsw, cmxolw, crndlw, cvisrfsw, cirrfsw, cirabsw)
    DESCRIPTION
    albcld_sw computes the cloud albedos. This calculation is based on sigma and cloud thickness in the old scheme (cldht60) and sigma, cloud thickness and latitude in the new scheme (cldht93).



    INPUT
    j   
       [integer]
    hi_cloud   
       [logical]
    mid_cloud   
       [logical]
    low_cloud   
       [logical]
    camtsw   
       [real]
    cmxolw   
       [real]
    crndlw   
       [real]

    INPUT/OUTPUT
    i   
       [real]
    cvisrfsw   
       [real]
    cirrfsw   
       [real]
    cirabsw   
       [real]


DATA SETS

None.


ERROR MESSAGES

None.


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