Aeronomie
Aeronomie is the branch of atmospheric science that studies the chemical composition and physical processes of the Earth's upper atmosphere, where solar radiation and energetic particles drive photochemical reactions and energy transfer. It focuses on the mesosphere, thermosphere, and ionosphere, regions where long mean free paths and low densities influence chemical pathways and the ionization state. The aim is to understand how composition changes in response to solar forcing, atmospheric dynamics, and particle precipitation, and how these changes affect radiation balance and communications systems.
In French and several other languages, the field is called aeronomie; in English, the term aeronomy is
Observations come from ground-based spectroscopy, occultation, lidar, radar, and in situ measurements on sounding rockets and
Key topics include ozone chemistry in the upper atmosphere, ionospheric composition, solar–terrestrial coupling, and the response