Modelling the near-infrared spectra of Jupiter using line-by-line methods

We have obtained long-slit, infrared spectra of Jupiter with the Anglo-Australian Telescope in the K and H bands at a resolving power of 2260. Using a line-by-line, radiative transfer model with the latest, improved spectral-line data for methane and ammonia, we derive a model of the zonal characteristics in the atmosphere of this giant planet. We fit our model to the spectra of the zones and belts visible at 2.1 μm using different distributions of cloud opacities. The modelled spectra for each region match observations remarkably well at the K band and in low-pressure regions at the H band. Our results for the upper deck cloud distribution are consistent with previous models fitted to low-resolution, grism spectra. The ability to obtain and model high-resolution planetary spectra, in order to search for weakly absorbing atmospheric constituents, can provide better constraints on the chemical composition of planetary atmospheres.