Color and aerosol changes in Jupiter after a North Temperate Belt disturbance

Icarus Elsevier BV 352 (2020) 114031

Authors:

S Pérez-Hoyos, A Sánchez-Lavega, Jf Sanz-Requena, N Barrado-Izagirre, O Carrión-González, A Anguiano-Arteaga, Pgj Irwin, As Braude

The transit spectra of Earth and Jupiter

ICARUS 242 (2014) 172-187

Authors:

PGJ Irwin, JK Barstow, NE Bowles, LN Fletcher, S Aigrain, J-M Lee

Stormy water on Mars: the distribution and saturation of atmospheric water during the dusty season

Science American Association for the Advancement of Science (2020)

Authors:

AA Fedorova, F Montmessin, O Korablev, M Luginin, A Trokhimovskiy, DA Belyaev, NI Ignatiev, F Lefèvre, Juan Alday, Patrick Irwin, Kevin Olsen, J-L Bertaux, E Millour, A Määttänen, A Shakun, AV Grigoriev, A Patrakeev, S Korsa, N Kokonkov, L Baggio, F Forget, Colin Wilson

Abstract:

The loss of water from Mars to space is thought to result from the transport of water to the upper atmosphere, where it is dissociated to hydrogen and escapes the planet. Recent observations have suggested large, rapid seasonal intrusions of water into the upper atmosphere, boosting the hydrogen abundance. We use the Atmospheric Chemistry Suite on the ExoMars Trace Gas Orbiter to characterize the water distribution by altitude. Water profiles during the 2018–2019 southern spring and summer stormy seasons show that high-altitude water is preferentially supplied close to perihelion, and supersaturation occurs even when clouds are present. This implies that the potential for water to escape from Mars is higher than previously thought.

Instrumental requirements for the study of Venus’ cloud top using the UV imaging spectrometer VeSUV

Advances in Space Research (2021)

Authors:

E Marcq, F Montmessin, J Lasue, B Bézard, KL Jessup, YJ Lee, CF Wilson, B Lustrement, N Rouanet, G Guignan

Abstract:

Ultraviolet spectral imaging has been a powerful tool to investigate the cloud top of Venus, allowing for measurement of several minor gases (especially SO , SO, O ), of cloud top aerosol's microphysical properties and of atmospheric dynamics through tracking of the unevenly distributed UV absorber. After a brief review of recent UV instruments that orbited around Venus, we present the results of a state-of-the-art radiative transfer model from Marcq et al. (2020) to derive the spectral resolution and Signal-to-Noise ratio (SNR) required to derive abundances of these gases, retrieve optical properties of the aerosols beyond our current knowledge. This leads us to propose a two-channel UV hyperspectral push-broom imager called VeSUV (standing for Venusian Spectroscopy in UV) whose technical characteristics will improve on existing measurements by a factor of at least 2, and which is well suited to the integration into the payload of future low Venus orbit platforms such as the proposed EnVision mission to ESA M5 call. 2 3

Isotopic fractionation of water and its photolytic products in the atmosphere of Mars

Nature Astronomy Springer Nature (2021)

Authors:

Juan Alday Parejo, Alexander Trokhimovskiy, Patrick GJ Irwin, Colin Wilson, Franck Montmessin, Franck Lefévre, Anna A Fedorova, Denis A Belyaev, Kevin S Olsen, Oleg Korablev, Margaux Vals, Loïc Rossi, Lucio Baggio, Jean-Loup Bertaux, Andrey Patrakeev, Alexey Shakun

Abstract:

The current Martian atmosphere is about five times more enriched in deuterium than Earth’s, providing direct testimony that Mars hosted vastly more water in its early youth than nowadays. Estimates of the total amount of water lost to space from the current mean D/H value depend on a rigorous appraisal of the relative escape between deuterated and non-deuterated water. Isotopic fractionation of D/H between the lower and the upper atmospheres of Mars has been assumed to be controlled by water condensation and photolysis, although their respective roles in influencing the proportions of atomic D and H populations have remained speculative. Here we report HDO and H2O profiles observed by the Atmospheric Chemistry Suite (ExoMars Trace Gas Orbiter) in orbit around Mars that, once combined with expected photolysis rates, reveal the prevalence of the perihelion season for the formation of atomic H and D at altitudes relevant for escape. In addition, while condensation-induced fractionation is the main driver of variations of D/H in water vapour, the differential photolysis of HDO and H2O is a more important factor in determining the isotopic composition of the dissociation products.