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Hot Terrestrial Exo-planet Atmospheres: preparing new generation instrument observations with a global climate model

Periodic Reporting for period 1 - Hot-TEA (Hot Terrestrial Exo-planet Atmospheres: preparing new generation instrument observations with a global climate model)

Reporting period: 2018-09-01 to 2020-08-31

The rapid growth of extra-solar planet (ESP) discovery and characterisation over the last two decades increases our hope to detect life signatures in other worlds in the near future. Given the variety of planetary atmospheres in our Solar System and the number of ESP observed so far, a vast diversity among ESP climate is expected. The study of ESP atmospheres is nowadays seen as the new frontier in Astrophysics, crucial for typifying planets in the habitable zone. Innovative and promising techniques, used so far to identify hot-Jupiter atmospheres, are envisaged to detect Earth-size planet atmospheres by exploiting high resolution spectrographs and large telescopes. To tackle this challenge, major efforts are devoted to 1) find closest ESP targets with the strongest atmospheric signature 2) develop 3D theoretical tools to predict realistic climates. In the perspective of detecting more and more close-in-orbit hot terrestrial planets, Hot-TEA proposes to address observational prospects to Venus-like planets, with the goal of studying how the planet’s atmosphere modifies the observables. With mass and radius similar to the Earth, but a completely different climate, Venus is the best analogue of those future targets.
The project has achieved most of its objectives and milestones for the period, with relatively minor deviations:
- Identify favourable targets and observable. A number of favourable targets were identified to provide 3D model simulations of Venus-like planets (Trappist 1c and Trappist 1d). The atmosphere of those planets will be likely observable in the future by forthcoming high-resolution instrumentation (JWST, HIRES/ELT).
- Set up the LMD Generic General Circulation Model for Venus-like planets. The results were validated using as reference the Venus GCM, which is a state-of-the-art model used to study the atmosphere of Venus from the surface to the thermosphere.
- Provide predicted observable spectra of exo-Venus obtained varying the abundances and the radii of the aerosols in the Venus atmosphere.
- Provide solid basis for future model development at the host institute. Although the project ended in August 2020, the long-term objectives of the project are still in line with the strategy of the IA Team, which is willing to invest in modeling extrasolar planet atmosphere in the future. The 3D model installed and set-up in the IA cluster is currently in use by a MSc student that I am supervising and will be in the future used by PhD students involved in IA funded projects.
The work carried out during the Marie Curie project “Hot-TEA” followed three objectives: 1) achieving the scientific goals the project 2) developing and increasing my network of collaborators in the exoplanetary science community 3) training undergraduate/master students of my host institute Instituto de Astrofísica e Ciências do Espaço(IA)/FC.ID on the use of modeling tools to study extrasolar planets atmosphere.

Four publications on referred International journals during the course of the project, resulted from on-going and previous collaborations with colleagues with a strong expertise in the field of Solar System planets. Two are published via open access on 1) Journal of Geophysical Research (planet), and 2) Earth, Planet and Space and other two are under review on Icarus and Experimental Astronomy. All them include the reference to the Marie Sklodowska-Curie Actions funding in the acknowledgment.
1. Impact of gravity waves on the middle atmosphere of Mars: a non-orographic gravity wave parameterization based on Global Climate modeling and MCS observations, G. Gilli et al. 2020;
2. Evaluation of the retrieval method for the temperature and wind velocity profiles of Venusian night-side mesosphere from mid-infrared CO2 absorption line observed by heterodyne spectroscopy, Takami et al. 2020;
3. Observability of temperate exoplanets with ARIEL, Encrenaz, T; Coustenis, A.; Gilli, G.; Marcq, E.; Ollivier M.; Tinetti, G., Experimental Astronomy, under revision
4. Venus' upper atmosphere revealed by a GCM: I. Structure and variability of the circulation, T. Navarro, G. Gilli; G. Schubert; S. Lebonnois; F. Lefevre; D. Quirino, Icarus, under revision
On top of the scientific activities, since October 2018 I am also co-leading the ARIEL (ESA space mission selected to be launched in 2028 ) Working Group on “Synergies with Solar System Planetary Atmosphere”. In addition, I was co-organizer and SOC member of the Europlanet Workshop S-SAIL: Solar System Atmospheres’ Investigation and exopLanets, June 2019, Lisbon ( ), and of TOE3: Toward other Earth: from Solar System to Exoplanet, June 2020, Portugal.
The latter was finally canceled because of the covid-19 pandemic evolution in the world (
Other activities and objectives foreseen in the original plan could not be realized either, because of the development of the pandemic situation.
In addition, I was invited to give talks to Early career students on Funding opportunity by UE, in particularly “Marie Curie opportunities”, “gender balance in Science”. I am currently co-supervising a phD Thesis together with IA team members, I am supervising 2 MSc Thesis of students of the Faculty of Science of Lisbon, and I took part in several outreach events organized by the IA, to disseminate the results of the project.
The project Hot-TEA had a positive and beneficial impact on my career and the host institution since the beginning.
I was invited to join the Scientific Consortium and lead a Working Group of the ARIEL/ESA mission on “Synergies with Solar System Planets”, and I co-organized a workshop, in Lisbon, Portugal, with IA team member on the topic of Solar System planet atmosphere and Exoplanets. I am currently vice-chair and Portuguese representative in the Spanish/Portuguese Hub of the Europlanet Society. I was also involved in the organization (SOC/LOC) of international conferences, that have been finally canceled/postponed, due to the pandemic.
- TOE3: Toward other Earth: from Solar System to Exoplanet, June 2020, Portugal (SOC)
- Reencontres du Vietnam Planets 2020
Together with the scientific work, those activities contributed not only to reinforce my network of collaborators on the field of exoplanets and foster the synergies between the two communities (e.g. solar system planets versus exoplanets), but also to make me gain maturity as a researcher by coordinating the WG tasks and defining the scientific objective of the workshop/conferences I was organizing. In addition, to increase the visibility of the project in the Portuguese society, the IA Science communication Team prepared a Press Release on IA-webpage to present the project main goals and possible impact on the Science in Portugal ( , ) and a press release on the paper published with the support of the project: