Model, software and database for line-mixing effects in the nu3 and nu4 bands of CH4 and tests using laboratory and planetary measurements - II : H2 (and He) broadening and the atmospheres of Jupiter and Saturn

International audience; The absorption shapes of the nu(2), nu(3) and nu(4) infrared bands of CH4 perturbed by H-2 in large ranges of pressure and temperature have been measured in the laboratory. In order to model these spectra, the theoretical approach accounting for line-mixing effects proposed for CH4-N-2 and CH4-air and successfully tested in the companion paper (1), is used. As before, state-to-state rotational rates are used together with some empirical parameters that are deduced from a fit of a single room temperature spectrum of the nu(3) band at about 50 atm. The comparisons between measured and calculated spectra in the nu(3) and nu(4) regions under a vast variety of conditions …