hr_ppart.md (4581B)
1 # HR\_PPart 2 3 The purpose of HR\_PPart is to perform radiative transfer computations 4 using high-resolution spectra that have been produced using 5 [Kspectrum](kspectrum.html). 6 Radiative transfer will actually be computed for every wavenumber that 7 defines the input high-resolution spectra. 8 This code is based on analytic radiative transfer solutions that are 9 valid only in the case of a emitting and absorbing, but non-scattering, 10 atmosphere. 11 This code should therefore be used, in the case of the terrestrial 12 atmosphere, for clear-sky LW computations only. 13 However, this code provides the possibility to use cloud data: the 14 scattering optical thickness is then partly integrated in the absorption 15 optical thickness. 16 This is only an approximation, not intended to provide accurate results. 17 Reference results are only achieved for a purely absorbing atmosphere. 18 19 [](images/emission_altitude_500-505.svg) 20 21 > Emission altitude signal in the [500-505] inv. cm spectral range, for 22 > a Mid-Latitude Summer standard atmosphere. 23 24 [](images/Te_signal_500-505.svg) 25 26 > Emission temperature signal in the [500-505] inv. cm spectral range, 27 > for a Mid-Latitude Summer standard atmosphere. 28 29 ## Quick start 30 31 - Sources: [tarball](downloads/hr_ppart.tgz) / 32 [pgp](downloads/hr_ppart.tgz.sig) 33 34 ### Prerequisites 35 36 Only a fortran compiler is needed (no external libraries). 37 The "gfortran" compiler has been used for development, but other common 38 compilers should work too (ifort, pgfortran, etc.). 39 40 ### Installation 41 42 Download and extract the archive (`tar -zxvf hr_ppart.tgz`); then move 43 into the HR\_PPart directory, and use the `make all` command to compile. 44 You should use the `make clean` command in the case you want to 45 recompile from scratch only (when include files are modified). 46 If only source files are modified, the `make all` command will recompile 47 modified files. 48 49 ### Run 50 51 HR\_PPart has been parallelized, which means you will have to launch it 52 using the "mpirun" command: 53 54 mpirun -np <NPROCS> ./analytic_RT.exe 55 56 with `<NPROCS>` the number of processes requested for the computation; 57 MacOS users might encounter a error where the OS considers the user 58 requested a number of processes higher than recommended. 59 You can bypass it using the `-oversubscribe` option: 60 61 mpirun -oversubscribe -np <NPROCS> ./analytic.exe 62 63 ## Usage 64 65 Before performing a computation, you should specify where 66 high-resolution spectra of interest are located: you need to provide a 67 link named `hires_spectra` within the `/data` directory. 68 This link should be pointing to a directory that contains all spectra 69 produced by Kspectrum for a given atmospheric profile, in addition to 70 the `composition.in` and `molparam.in` files used by Kspectrum in order 71 to produce these spectra. 72 This directory should also contain a simple ascii file named 73 `profile_parameters.in` with the following structure: 74 75 Input data for program "analytic_RT" 76 77 Temperature of ground (K) 78 294.0D+0 79 Temperature of space (K) 80 3.0D+0 81 Ground emissivity 82 1.0D+0 83 84 Simulation input is provided through the `data.in` and `options.in` 85 files (located in the main `HR_PPart` directory): 86 87 - the `options.in` file provides the possibility to perform a angular 88 integration, or perform a single-direction radiative transfer 89 computation. 90 It provides the possibility to use a specular or a diffuse reflective 91 ground. 92 It provides many options for pre-computing spectral data 93 (collision-induced opacities, water continuum). 94 The last options provide a way to disable the computation of 95 time-consuming results, and also to disable the recording of specific 96 spectral data, which should further speed up the computation. 97 98 - the `data.in` file lets the user specify the spectral 99 integration domain, the probe pressure (some results are computed at a given 100 "probe" pressure level) and the direction to use for a single-direction 101 radiative transfer computation. 102 103 Results are located into the `/results` directory; several 104 gnuplot scripts are provided in order to visualise various results. 105 106 ## License 107 108 Copyright © 2014-2018 Centre National de la Recherche Scientifique (CNRS) 109 Copyright © 2014-2018 |Méso|Star> 110 ([contact@meso-star.com](mailto:contact@meso-star.com)) 111 112 HR\_PPart is free software released under the CeCILL v2.1 license. 113 You are welcome to redistribute it under certain conditions; refer to 114 the 115 [license](http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.txt) 116 for details. 117