The ozone layer refers to a region of the atmosphere about 15–30 km above Earth’s surface that contains a relative abundance of ozone (but still a tiny amount compared to the rest of the air). Ozone is a molecule containing three oxygen atoms (instead of the two oxygen atoms in atmospheric oxygen). The layer is important because ozone absorbs ultraviolet light from the Sun, protecting life on Earth’s surface in the process.

This Reading provides background information on the underlying concepts in the Activities included in the Project Earth Science: Meteorology, Revised 2nd Edition. The Reading goes beyond what is found in the background information in the activities. The Reading can be used as supplementary information for the teacher, or to enhance classroom discussions.