art.md (3156B)
1 # Atmospheric Radiative Transfer 2 3 We propose a number of open-source codes selected within our 4 *A*tmospheric *R*adiative *T*ransfer toolchain. 5 Each code is released under the copyleft licenses, which means anyone 6 has the right to modify and redistribute the code within specific 7 conditions; please refer to their license for details. 8 9 The codes currently available are briefly described bellow : 10 11 - [Kspectrum](kspectrum.html) produces high-resolution synthetic spectra 12 of any gas mixture, in arbitrary thermodynamic conditions (pressure, 13 temperature and molar composition) from public spectroscopic 14 databases. 15 Please note this code does *NOT* compute application-specific 16 opacities (collision-induced absorption, continua, ...) and does *NOT* 17 perform radiative transfer computations. 18 This is all about adding energetic transitions contributions. 19 20 - [Kdistribution](kdistributio.html) produces k-distribution data sets 21 from the high-resolution spectra that have been produced by kspectrum. 22 The output spectral data is intended to be used subsequently by 23 radiative transfer codes that are based on the k-distribution spectral 24 model. 25 26 - [HR\_PPart](hr_ppart.html) performs atmospheric radiative transfer 27 computations using high-resolution spectra produced by kspectrum. 28 This code is based on analytic radiative transfer solutions, and is 29 suitable for non-scattering atmospheres: in the case of the 30 terrestrial atmosphere, it means in the LW, and for clear-sky 31 configurations only. 32 This version is intended to be used in the case of the terrestrial 33 atmosphere: it can compute collision-induced opacities and also the 34 water vapour continuum, in order to add these opacities to 35 high-resolution spectra, before actually performing radiative transfer 36 computations. 37 38 - [PPart\_LW](ppart_lw.html) performs atmospheric radiative transfer 39 computations using the k-distribution spectral model, in the LW part 40 of the spectrum. 41 This code is based on the same analytic solutions of radiative 42 transfer than HR\_PPart. 43 It was recently updated to use a variable quadrature order in each 44 spectral interval. 45 The atmosphere is supposed to absorb and emit radiation (LW 46 computation). 47 48 - [PPart\_SW](ppart_sw.html) performs atmospheric radiative transfer 49 computations using the k-distribution spectral model, in the SW part 50 of the spectrum. 51 Even if it is based on the same analytic radiative transfer solutions 52 than HR\_PPart and PPart\_LW, and should therefore not be suitable for 53 the SW range because of Rayleigh scattering, we still maintain this 54 tool as a toy model: the atmosphere is supposed to absorb solar 55 radiation only: scattering and self-emission are neglected. 56 57 - [Karine](karine.html) performs atmospheric radiative transfer 58 computations using the k-distribution spectral model, in the LW part 59 of the spectrum. 60 This code is based on a Monte-Carlo algorithm, which means scattering 61 (both by the gas and by clouds) is taken into account. 62 A inhomogeneous atmosphere is stratified into a succession of 63 homogeneous layers, that can also contain cloud particles and aerosol 64 particles.