Water formation in the upper atmosphere of the early Earth

Benjamin Fleury (1) , Nathalie Carrasco (1, 2) , Emmanuel Marcq (1) , Ludovic Vettier (3) , Anni Määttänen (1)

1 PLANETO - LATMOS
2 IUF - Institut Universitaire de France
3 LATMOS - Laboratoire Atmosphères, Milieux, Observations Spatiales

The water concentration and distribution in the early Earth's atmosphere are important parameters that contribute to the chemistry and the radiative budget of the atmosphere. If the atmosphere above the troposphere is generally considered as dry, photochemistry is known to be responsible for the production of numerous minor species. Here we used an experimental setup to study the production of water in conditions simulating the chemistry above the troposphere of the early Earth with an atmospheric composition based on three major molecules: N2, CO2, and H2. The formation of gaseous products was monitored using infrared spectroscopy. Water was found as the major product, with approximately 10% of the gas products detected. This important water formation is discussed in the context of the early Earth.

Keywords: planets and satellites: atmospheres; Earth; astrochemistry

Domains: Physics [physics]; Physics [physics]; Atmospheric and Oceanic Physics [physics.ao-ph]; Sciences of the Universe [physics]; Astrophysics [astro-ph]; Earth and Planetary Astrophysics [astro-ph.EP]

Benjamin Fleury, Nathalie Carrasco, Emmanuel Marcq, Ludovic Vettier, Anni Määttänen. Water formation in the upper atmosphere of the early Earth. The Astrophysical journal letters, 2015, 807 (2), pp.L29. ⟨10.1088/2041-8205/807/2/L29⟩. ⟨insu-01176058⟩