Abstract

This study examines the formation of the ozone layer (OL) in the Earth’s atmosphere and the physical mechanisms governing the attenuation of ultraviolet (UV) radiation reaching the Earth’s surface. The analysis suggests that the contribution of stratospheric ozone to the reduction of short-wave solar radiation may be smaller than is commonly assumed, while acknowledging that ultraviolet radiation also exerts a range of beneficial biological effects. Ozone is produced under the action of solar ultraviolet radiation below the ionosphere through the dissociation of atmospheric oxygen molecules. Its longest lifetime corresponds to the minimum temperature zone, leading to ozone accumulation above the tropopause and the formation of the observed ozone layer. The total atmospheric ozone content is extremely small, on the order of 10⁻⁶ relative to the total mass of air, which constrains its overall contribution to ultraviolet absorption. In contrast, molecular scattering by air provides substantial attenuation of ultraviolet radiation, despite the lower energy exchange in scattering events compared with absorption. Ozone depletion is commonly attributed to reactions involving halogen-containing compounds of both anthropogenic and natural origin, as well as to interactions with hydrogen predominantly generated within the atmosphere. Variations in ozone layer thickness, including the seasonal formation of so-called “ozone holes,” are shown to be consistent with natural processes and do not imply enhanced ultraviolet exposure at the Earth’s surface. The effectiveness of current mitigation strategies aimed at stratospheric ozone preservation, therefore, warrants reassessment. At the same time, increases in ground-level ozone are clearly linked to industrial activity and urban air pollution. In many developed regions, concentrations of this toxic gas periodically exceed recommended exposure limits, underscoring the need for targeted measures to control tropospheric ozone.

Keywords: Ozone layer; Ultraviolet radiation; Oxygen; Hydrogen; Molecular scattering