HR_PPart
The purpose of HR_PPart is to perform radiative transfer computations using high-resolution spectra that have been produced using Kspectrum. Radiative transfer will actually be computed for every wavenumber that defines the input high-resolution spectra. This code is based on analytic radiative transfer solutions that are valid only in the case of a emitting and absorbing, but non-scattering, atmosphere. This code should therefore be used, in the case of the terrestrial atmosphere, for clear-sky LW computations only. However, this code provides the possibility to use cloud data: the scattering optical thickness is then partly integrated in the absorption optical thickness. This is only an approximation, not intended to provide accurate results. Reference results are only achieved for a purely absorbing atmosphere.
Emission altitude signal in the [500-505] inv. cm spectral range, for a Mid-Latitude Summer standard atmosphere.
Emission temperature signal in the [500-505] inv. cm spectral range, for a Mid-Latitude Summer standard atmosphere.
Quick start
Prerequisites
Only a fortran compiler is needed (no external libraries). The "gfortran" compiler has been used for development, but other common compilers should work too (ifort, pgfortran, etc.).
Installation
Download and extract the archive (tar -zxvf hr_ppart.tgz
); then move
into the HR_PPart directory, and use the make all
command to compile.
You should use the make clean
command in the case you want to
recompile from scratch only (when include files are modified).
If only source files are modified, the make all
command will recompile
modified files.
Run
HR_PPart has been parallelized, which means you will have to launch it using the "mpirun" command:
mpirun -np <NPROCS> ./analytic_RT.exe
with <NPROCS>
the number of processes requested for the computation;
MacOS users might encounter a error where the OS considers the user
requested a number of processes higher than recommended.
You can bypass it using the -oversubscribe
option:
mpirun -oversubscribe -np <NPROCS> ./analytic.exe
Usage
Before performing a computation, you should specify where
high-resolution spectra of interest are located: you need to provide a
link named hires_spectra
within the /data
directory.
This link should be pointing to a directory that contains all spectra
produced by Kspectrum for a given atmospheric profile, in addition to
the composition.in
and molparam.in
files used by Kspectrum in order
to produce these spectra.
This directory should also contain a simple ascii file named
profile_parameters.in
with the following structure:
Input data for program "analytic_RT"
Temperature of ground (K)
294.0D+0
Temperature of space (K)
3.0D+0
Ground emissivity
1.0D+0
Simulation input is provided through the data.in
and options.in
files (located in the main HR_PPart
directory):
the
options.in
file provides the possibility to perform a angular integration, or perform a single-direction radiative transfer computation. It provides the possibility to use a specular or a diffuse reflective ground. It provides many options for pre-computing spectral data (collision-induced opacities, water continuum). The last options provide a way to disable the computation of time-consuming results, and also to disable the recording of specific spectral data, which should further speed up the computation.the
data.in
file lets the user specify the spectral integration domain, the probe pressure (some results are computed at a given "probe" pressure level) and the direction to use for a single-direction radiative transfer computation.
Results are located into the /results
directory; several
gnuplot scripts are provided in order to visualise various results.
License
Copyright © 2014-2018 Centre National de la Recherche Scientifique (CNRS)
Copyright © 2014-2018 |Méso|Star>
(contact@meso-star.com)
HR_PPart is free software released under the CeCILL v2.1 license. You are welcome to redistribute it under certain conditions; refer to the license for details.