Modelling planetary atmosphere with a GCM
The Generic Planetary Climate Model is General Climate Model (GCM) developed at LMD/IPSL to model the temporal evolution of planetary atmospheres based on 3D hydrodynamics and realsitic radiatve transfer. As a part of this project, I am working on parametrisation of small scale processes that are not resolved by the grid of the model, such as convection and gravity waves, in the atmospheres of giant planets. I am also aiming to study, from a theoretical and numerical point of view, large-scale gravity waves in the deep atmosphere of Venus.
Atmospheric dynamics of Neptune and Uranus.
Currently, I am working on a parametrisation of convection based on a thermal plume model initially developed for the Earth boudary layer by Hourdin et al. (2002). This study is part of the ANR SOUND project.
Wave activity below the clouds of Venus with the IPSL Venus GCM
Lebonnois S., Le Saux A., Garate-Lopez I., Plougonven R. (in prep)
In the current version of the Venus GCM the zonal wind profile above 40 km altitude corresponds to the observations, while below the simulated wind is too weak. Whereas it was the opposite case in a previous version of the GCM. At the same time, we notice between the two versions, the disappearance of waves in the deep atmosphere. It turns out that these are inertial gravity waves whose source is located near the poles, North and South, and that they propagate downwards and towards the equator. The structure of these low frequency waves is strongly influenced by the solar heating and infrared cooling rates in the atmosphere. However, these two parameters are not well known at present because we have few observations that allow us to constrain them.