H-2 vibrational temperatures in the upper atmosphere of Jupiter

Mathieu Barthelemy (1) , Jean Lilensten (1) , C. Parkinson (2, 3)

1 LPG - Laboratoire de Planétologie de Grenoble
2 CALTECH - MS 150-21
3 JPL - Jet Propulsion Laboratory

The Jovian upper atmosphere has been extensively studied over the past few decades with many observations having been made. Typically, the H2 vibrational temperatures have always been considered as kinetic temperatures in modelling efforts to date. However, recent studies have shown that this assumption is not robust and that we can expect enhanced vibrational temperatures due to overlapping lines to play an important role in the thermosphere of Jupiter. In this paper, we use a radiative transfer code to compute the total integrated H Lyman $\alpha$ dayglow intensity taking into account the overlapping with H2 hot bands. We show that an atmosphere with H2 vibrational temperatures equal to about 1.4 to 1.5 times kinetic reproduce the Voyager observations.

Keywords: ultraviolet: solar system; radiative transfer; planets and satellites: individual: Jupiter

Domains: Sciences of the Universe [physics]; Astrophysics [astro-ph]

Mathieu Barthelemy, Jean Lilensten, C. Parkinson. H-2 vibrational temperatures in the upper atmosphere of Jupiter. Astronomy and Astrophysics - A&A, 2005, 437 (1), pp.329-331. ⟨10.1051/0004-6361:20040257⟩. ⟨insu-00355938⟩