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.
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
HR_PPart has been parallelized, which means you will have to launch it using the "mpirun" command:
mpirun -np <NPROCS> ./analytic_RT.exe
<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
mpirun -oversubscribe -np <NPROCS>./analytic.exe
Prerequistes: 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.).
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
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
Input data for program "analytic_RT" Temperature of ground (K) 294.0D+0 Temperature of space (K) 3.0D+0 Ground emissivity 1.0D+0Simulation input is provided through the
options.infiles (located in the main
options.infile 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.
data.infile 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.
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.