Volcanic gas plumes’ effect on the spectrum of Venus

Abstract

Venus is home to thousands of volcanoes, with a wide range of volumes and sizes. Its surface is relatively young, with a temperature of approximately 735 K and an atmosphere of 92 bar. Past and possible ongoing volcanic outgassing is expected to provide a source to the sustenance of this massive atmosphere, dominated by CO${}_2$ and SO${}_2$. The lower atmosphere can be investigated in the near-infrared transparency windows on the nightside, such as the $2.3\mu m$ thermal emission window, which provides a chance of detection of species with volcanic origin, such as water vapor.

The Planetary Spectrum Generator was used to simulate the nightside $2.3\mu m$ thermal emission window of Venus. We simulated the effect of a volcanic gas plume rising to a ceiling altitude, for species such as H${}_2$O, CO, OCS, HF and SO${}_2$. The sensitivity of the radiance spectrum at different wavelengths was explored as an attempt to qualitatively access detection for future measurements of both ground-based and space-instrumentation.

We conclude from our qualitative analysis that for the H${}_2$O, CO and OCS plumes simulated there is potential to achieve a detection in the future, given a minimum required signal-to-noise ratio of 50. For SO${}_2$ and HF plumes, a higher signal-to-noise ratio would be needed.