Atmospheric Radiative Transfer
We propose a number of open-source codes selected within our Atmospheric Radiative Transfer toolchain. Each code is released under the copyleft licenses, which means anyone has the right to modify and redistribute the code within specific conditions; please refer to their license for details.
The codes currently available are briefly described bellow :
Kspectrum produces high-resolution synthetic spectra of any gas mixture, in arbitrary thermodynamic conditions (pressure, temperature and molar composition) from public spectroscopic databases. Please note this code does NOT compute application-specific opacities (collision-induced absorption, continua, ...) and does NOT perform radiative transfer computations. This is all about adding energetic transitions contributions.
Kdistribution produces k-distribution data sets from the high-resolution spectra that have been produced by kspectrum. The output spectral data is intended to be used subsequently by radiative transfer codes that are based on the k-distribution spectral model.
HR_PPart performs atmospheric radiative transfer computations using high-resolution spectra produced by kspectrum. This code is based on analytic radiative transfer solutions, and is suitable for non-scattering atmospheres: in the case of the terrestrial atmosphere, it means in the LW, and for clear-sky configurations only. This version is intended to be used in the case of the terrestrial atmosphere: it can compute collision-induced opacities and also the water vapour continuum, in order to add these opacities to high-resolution spectra, before actually performing radiative transfer computations.
PPart_LW performs atmospheric radiative transfer computations using the k-distribution spectral model, in the LW part of the spectrum. This code is based on the same analytic solutions of radiative transfer than HR_PPart. It was recently updated to use a variable quadrature order in each spectral interval. The atmosphere is supposed to absorb and emit radiation (LW computation).
PPart_SW performs atmospheric radiative transfer computations using the k-distribution spectral model, in the SW part of the spectrum. Even if it is based on the same analytic radiative transfer solutions than HR_PPart and PPart_LW, and should therefore not be suitable for the SW range because of Rayleigh scattering, we still maintain this tool as a toy model: the atmosphere is supposed to absorb solar radiation only: scattering and self-emission are neglected.
Karine performs atmospheric radiative transfer computations using the k-distribution spectral model, in the LW part of the spectrum. This code is based on a Monte-Carlo algorithm, which means scattering (both by the gas and by clouds) is taken into account. A inhomogeneous atmosphere is stratified into a succession of homogeneous layers, that can also contain cloud particles and aerosol particles.
