Temperature, Clouds, and Aerosols in the Terrestrial Bodies of the Solar System
Résumé
This chapter is intended to provide a concise overview of the state of knowledge regarding the temperature, clouds, and aerosols of the terrestrial bodies of our Solar System, namely Mars, Venus, and Titan. These bodies are the planetary objects that most resemble the Earth. The atmosphere of each body is described in terms of composition and vertical structure. We distinguish and compare the extent of the various atmospheric compartments that form the atmospheric column, from the troposphere up to the thermosphere. The temperature structure is then presented, and the main causes known for explaining its variations on each body are listed. The specific roles of waves, radiation, as well as convection in shaping temperature profiles are then discussed. In a second part, the particulate components of these atmospheres, clouds and aerosols, are described in terms of their physical properties (composition, optical properties) and of their variability in both space and time. Mars , Venus, and Titan exhibit a remarkable variety of clouds and aerosols. Our knowledge about them has made considerable progress thanks to the success of space missions during the last two decades, while in parallel theoretical models have improved to the point that three-dimensional Global Climate Models now include the detailed physics of clouds and aerosols. As a result, it is now widely recognized that particulates play a key role in forcing the climate and the evolution of these bodies.
Mots clés
Mars
Venus
Tittan
Atmospheres
Diurnal solar forcing
Atmospheric waves
Radiative equilibrium
Photodissociation
Breaking wave
Tides
Solar System
Radiative transfer
Troposphere
Stratosphere
Mesosphere
Thermosphere
Radiation
Boundary layer
Scale height
Greenhouse
Infrared
Surface temperature
Cloud layer
Thermodynamic equilibrium
Thermal behavior
Tropopause
Stratopause
Mesopause
Isothermal
Gravity wave
Radiative-convective equilibrium
Dust storms
Diabatic
Mesoscale models
Mars Odyssey
Mars Express
Mars Reconnaissance
Orbiter
Venus Express
Cassini