Abstract

In CO2-rich atmospheres such as that of Venus, the study of water vapor requires the use of H2O collision parameters for CO2. However, due to a lack of data, models still use collision parameters for air to estimate the abundance of water vapor in this type of atmosphere. In this thesis, new experimental laboratory measurements of the collision parameters of H2O, HDO, and D2O by CO2 were carried out. These were then used as the basis for dedicated theoretical calculations. Their impact was evaluated using radiative transfer simulations applied to the atmosphere of Venus, under conditions close to those of future observations by the European EnVision mission. The results clearly show that using collision parameters for air instead of CO2 can lead to an overestimation of nearly 40% of the abundance of water vapor in the mesosphere and to inversion difficulties in the troposphere. This work thus provides essential elements for improving the spectral analysis of CO2-rich atmospheres.

Jury

  • Dr. Ha TRAN (Sorbonne University), Chair
  • Prof. Muriel LEPÈRE (University of Namur), Secretary
  • Dr. Emmanuel MARCQ (University of Versailles)
  • Dr. David JACQUEMART (Sorbonne University)
  • Dr. Laurence RÉGALIA (University of Reims)
  • Dr. Séverine ROBERT (Royal Institute for Space Aeronomy, Belgium)