Meridional variations of C${}_2$H${}_2$ in Jupiter's stratosphere from Juno UVS observations

Abstract

The UVS instrument on the Juno mission records far-ultraviolet reflected sunlight from Jupiter. These spectra are sensitive to the abundances of chemical species in the upper atmosphere and to the distribution of the stratospheric haze layer. We combine observations from the first 30 perijoves of the mission in order to study the meridional distribution of acetylene (C${}_2$H${}_2$) in Jupiter's stratosphere. We find that the abundance of C${}_2$H${}_2$ decreases towards the poles by a factor of 2-4, in agreement with previous analyses of mid-infrared spectra. This result is expected from insolation rates: near the equator, the UV solar flux is higher, allowing more C${}_2$H${}_2$ to be generated from the UV photolysis of CH${}_4$. The decrease in abundance towards the poles suggests that horizontal mixing rates are not rapid enough to homogenize the latitudinal distribution.

Accepted in JGR Planets. 19 pages, 3 figures

References in corpus (2)

• Assessing the long-term variability of acetylene and ethane in the stratosphere of Jupiter
• Jupiter in the ultraviolet: acetylene and ethane abundances in the stratosphere of Jupiter from Cassini observations between 0.15 and 0.19 $\mu$m

Cited by in corpus (1)

• Grid of pseudo-2D chemistry models for tidally locked exoplanets -- II. The role of photochemistry