Building a Planet Atmosphere: Fundamental Physics and Chemistry

TL;DR

This chapter offers a comprehensive overview of planetary atmospheric physics and chemistry, covering fundamental concepts, structure, composition, and differences between terrestrial and gaseous atmospheres.

Contribution

It synthesizes key principles of atmospheric physics and chemistry, integrating basic derivations, chemical processes, and atmospheric components in a unified framework.

Findings

Retention mechanisms against thermal evaporation

Vertical atmospheric profiles shaped by convection and radiation

Differences between terrestrial and gaseous atmospheres

Abstract

This chapter provides an overview of the basic concepts foundational to atmospheric physics and chemistry. We discuss the retention of atmospheres against thermal evaporation and the global energy balance of planets. We present simple derivations of the vertical profile of an atmosphere, which may be shaped by convective and radiative transport. We then briefly touch upon the three-dimensional atmospheric structure, as shaped by circulation patterns. We describe how the abundances of chemical species in the atmosphere are determined, starting with the assumption of chemical equilibrium and then expanding to various disequilibrium effects. We introduce the particles that can be important components of atmospheres (clouds and hazes) and sketch out some of their complexity. Finally, we review some of the differences between atmospheres of terrestrial and gaseous worlds.