Airglow in the Earth atmosphere: basic characteristics and excitation mechanisms

Abstract

The Earth’s middle and upper atmosphere is a region exhibiting non-thermal emissions of electromagnetic radiation generally known as airglow. Airglow is a ubiquitous phenomenon and comprises a large number of atomic and molecular emissions in the ultraviolet, the visible and the near-infrared spectral regions. The main purpose of this article is to provide an overview of the basic characteristics of the airglow, the most important airglow emissions occurring in the terrestrial atmosphere—with a focus on nighttime or nightglow emissions—as well as the current scientific understanding of their excitation mechanisms.