Atmospheres across the Universe

Informazioni relative al progetto

ATMO

ID dell’accordo di sovvenzione: 757858

DOI

10.3030/757858

Progetto chiuso

Data della firma CE 30 Ottobre 2017

Data di avvio 1 Febbraio 2018

Data di completamento 31 Luglio 2023

Finanziato da

• EXCELLENT SCIENCE - European Research Council (ERC)

Costo totale

€ 1 500 000,00

Contributo UE

€ 1 500 000,00

Coordinato da

COMMISSARIAT A L ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
France

Periodic Reporting for period 4 - ATMO (Atmospheres across the Universe)

Periodo di rendicontazione: 2022-08-01 al 2023-07-31

Sintesi del contesto e degli obiettivi generali del progetto

Which molecules are present in the atmosphere of exoplanets? What are their mass, radius and age? Do they have clouds, convection (atmospheric turbulence), or a circulation induced by irradiation? These questions are fundamental in exoplanetology to better understand planet formation and exoplanet habitability with the James Webb Space Telescope (JWST).

This project aims at characterizing the impact of diabatic convection (i.e. with source terms) in the atmosphere of stars, brown dwarfs, and exoplanets and its interaction with the circulation in the case of irradiated planets. By developing innovative numerical models, we will characterize the effect of the diabatic instability induced by chemical transitions (e.g. CO/CH4) with radiative transfer and its interaction with the global circulation in the atmosphere. We will then predict and interpret the mass, radius, and chemical composition of exoplanets that will be observed with future missions such as the JWST.

Thermo-compositional diabatic convection is a new concept proposed in Tremblin et al. 2019 that encompass several well known convective systems in which source terms are important (thermohaline convection in Earth oceans, fingering convection in stars, moist convection in Earth atmosphere, steam/liquid water convection in cooling systems, and CO/CH4 radiative convection in the atmosphere of brown dwarfs and extrasolar giant exoplanets).

Lavoro eseguito dall’inizio del progetto fino alla fine del periodo coperto dalla relazione e principali risultati finora ottenuti

- We have developed a massively-parallel convection code called ARK that has been used to perform “grand challenge” simulations on the entire GPU supercomputer Jean Zay and Adastra in France. The code is publicly available at https://gitlab.erc-atmo.eu/erc-atmo/ark
- We have performed 3D simulations of the circulation of the atmospheres on Hot Jupiters on 1000 years, showing that on these long timescales, the deep atmosphere becomes hot. This fully confirms our theory for the explanation of the “radius inflation puzzle”, an astrophysical problem that has not been explained for 20 years.
- We have developed a full theoretical framework to study CO/CH4 convection in brown dwarfs. It turns out that it exceeds by far the problematic of the ERC: we have shown that thermohaline and moist convection in Earth atmosphere and oceans can also be described by our general theory, and it opens new perspectives in the understanding of these convective phenomena. It could also be used to understand complex behaviour such as the “boiling crisis” in the cooling systems of nuclear power plants (a subject that is of interest for CEA which is the French nuclear research lab).

Progressi oltre lo stato dell’arte e potenziale impatto previsto (incluso l’impatto socioeconomico e le implicazioni sociali più ampie del progetto fino ad ora)

The theory of diabatic convection is a major achievement in the understanding of convective processes. We have extended the theory to include shear flows and also magnetized flows and we have studied the generation of magnetic fields by convective dynamos on the largest supercomputer in France. The theory can then be used to understand differential rotation and the generation of magnetic fields in the Sun and stars. Sheared convection can also be used to study the formation of jets in planetary atmospheres.

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