Thibault Cavalié — Millimeter/submillimeter observations and modeling of chemistry and dynamics in Solar System Giant Planet atmospheres

Quand :
27 novembre 2018 @ 11 h 00 min – 12 h 00 min
2018-11-27T11:00:00+01:00
2018-11-27T12:00:00+01:00
Où :
Univers 21

Better understanding Solar System Giant Planet formation and evolution requires in situ measurements, remote sensing observations either with telescopes or planetary missions, and modeling. While more and more exoplanets are discovered every day and while we will better characterize them with new observatories like JWST, the planets of the Solar System remain our local laboratory for studying formation and evolution of such bodies. The (sub)millimeter domain, owing to the very high spectral resolution of the heterodyne technique and to the ever increasing spatial resolution and sensitivity of new observatories like ALMA, is suitable for determining planetary atmospheric composition and dynamics when coupled with appropriate radiative transfer, photochemical or thermochemical modeling.

 

In this seminar, I will summarize 10 years of observations and modeling of the Solar System Giant Planets I have been involved in.

I will first show that thermochemical modeling of the deep tropospheres of the Giant Planets can help us establish their deep composition to constrain their formation processes. The next step is the participation in an atmospheric probe proposal for the Ice Giants, and the development of its mass spectrometer, in preparation for a NASA-ESA joint flagship mission to these distant worlds.

I will also show how observations and time-dependent 1D or 2D photochemical modeling have enabled us to improve our understanding of how the composition and chemistry in the stratospheres of the Giant Planets are altered by seasons and external sources. With ALMA, it is now even possible to directly measure winds in the stratospheres of the Giant Planets to constrain their stratospheric circulation.

Finally, I will present how the Submillimetre Wave Instrument of the Jupiter Icy Moons Explorer (JUICE) mission will allow us, in about a decade from now, to monitor Jupiter’s atmosphere, both in terms of chemistry and dynamics, and with spectral and spatial resolutions and temporal coverage never achieved before.