Speaker
Description
We report on the detection and upper-limit of SO$_2$, SO$_3$, OCS, H$_2$S, CS, H$_2$CO, O$_3$, NH$_3$, HCN, N$_2$O, NO$_2$, and HO$_2$ above the cloud deck using the SOIR instrument on-board Venus Express [1, 2].
The SOIR instrument [3] performed solar occultation measurements in the IR region (2.2 - 4.3 µm) at a spectral resolution of 0.12 cm$^{-1}$, among the highest of all space instruments. It combined an echelle spectrometer and an Acousto-Optical Tunable Filter for the order selection. SOIR performed more than 1500 solar occultation measurements leading to about two millions spectra [4].
The wavelength range probed by SOIR allows a detailed chemical inventory of the Venus mesosphere, above 60km, at the terminator with an emphasis on vertical distribution of the gases.
In this work, we report detections of minor species poorly constrained so far in the Venusian mesosphere. The implications of these detections for the chemistry will be addressed, as will possible cross-correlations between different species.
References:
[1] Mahieux, A., et al. (2023), Icarus, Under review.
[2] Mahieux, A., et al. (2023), Icarus, In preparation.
[3] Mahieux, A., et al. (2008), Applied Optics, 47.
[4] Vandaele , A.C., et al. (2016), Adv. Space Res., 57.
