Module atmos_radon

Module atmos_radon_mod

Contact: William Cooke
Reviewers: Larry Horowitz
Change History: WebCVS Log

OVERVIEW

This code allows the implementation of an extremely simplified radon tracer in the FMS framework.

It should be taken as the implementation of a very simple tracer which bears some characteristics of radon.

This module presents an implementation of a tracer. It should be taken as representing radon only in a rudimentary manner.

OTHER MODULES USED

                   fms_mod
          time_manager_mod
          diag_manager_mod
        tracer_manager_mod
         field_manager_mod
atmos_tracer_utilities_mod

PUBLIC INTERFACE

atmos_radon_sourcesink:: The routine that calculate the sources and sinks of radon.
atmos_radon_init:: The constructor routine for the radon module.
atmos_radon_end:: The destructor routine for the radon module.

PUBLIC DATA

None.

PUBLIC ROUTINES

atmos_radon_sourcesink

call atmos_radon_sourcesink (lon, lat, land, pwt, radon, radon_dt, Time, kbot)

DESCRIPTION

This is a very rudimentary implementation of radon.

It is assumed that the Rn222 flux is 3.69e-21 kg/m*m/sec over land for latitudes < 60N

Between 60N and 70N the source = source * .5

Rn222 has a half-life time of 3.83 days, which corresponds to an e-folding time of 5.52 days.

INPUT

`lon`	Longitude of the centre of the model gridcells [real, dimension(:,:)]
`lat`	Latitude of the centre of the model gridcells [real, dimension(:,:)]
`land`	Land/sea mask. [real, dimension(:,:)]
`pwt`	The pressure weighting array. = dP/grav [real, dimension(:,:,:)]
`radon`	The array of the radon mixing ratio. [real, dimension(:,:,:)]
`Time`	Model time. [type(time_type)]
`kbot`	Integer array describing which model layer intercepts the surface. [integer, optional, dimension(:,:)]

OUTPUT

radon_dt The array of the tendency of the radon mixing ratio.
[real, dimension(:,:,:)]

atmos_radon_init

call atmos_radon_init

DESCRIPTION

A routine to initialize the radon module.

INPUT

`mask`	optional mask (0. or 1.) that designates which grid points are above (=1.) or below (=0.) the ground dimensioned as (nlon,nlat,nlev). [real, optional, dimension(:,:,:)]
`Time`	Model time. [type(time_type)]
`axes`	The axes relating to the tracer array dimensioned as (nlon, nlat, nlev, ntime) [integer, dimension(4)]

INPUT/OUTPUT

`r`	Tracer fields dimensioned as (nlon,nlat,nlev,ntrace). [real, dimension(:,:,:,:)]

atmos_radon_end
```
call atmos_radon_end 
```
DESCRIPTION

This subroutine writes the version name to logfile and exits.

DATA SETS

None.

ERROR MESSAGES

None.

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