Uranus' stratospheric HCl upper limit from Herschel/SPIRE

Abstract

Herschel/SPIRE observations of Uranus are used to search for stratospheric hydrogen chloride (HCl) emission at 41.74 cm${}^{-1}$. HCl was not detected and instead 3$\sigma$ upper limits were determined; $<$6.2 ppb ($<$2.0$\times$10${}^{14}$ molecules/cm${}^2$) for a 0.1 mbar step profile and $<$0.40 ppb ($<$1.2$\times$10${}^{14}$ molecules/cm${}^2$) for a 1 mbar step profile. HCl is expected to have an external source and these upper limits are consistent with abundances of other external species (CO, H${}_2$O, CO${}_2$) and a solar composition source.

4 pages, 1 figure, accepted for publication in RNAAS 2020

References in corpus (1)

• Mid-Infrared Spectroscopy of Uranus from the Spitzer Infrared Spectrometer: 2. Determination of the Mean Composition of the Upper Troposphere and Stratosphere