The ozone layer is a thin, glowing layer around the Earth’s atmosphere that protects us from harmful sun rays. It acts like a shield, blocking dangerous ultraviolet(UV) radiation to keep the planet and all living things safe. This stratosphere region contains a high concentration of ozone (O₃) molecules. The ozone layer’s thickness varies depending on altitude and geography. Generally, ozone levels are thicker at the poles and thinner near the equator, but this can change seasonally.
Christian Friedrich Schonbein first discovered ozone in 1839. Key figures like Sydney Chapman, Joseph Lagrange, and later, Molina, Rowland, and Crutzen, played crucial roles in revealing the importance of ozone in protecting life on Earth.
The breakdown of ozone molecules causes a weakening or “hole” in the ozone layer, known as an ozone hole. Certain man-made chemicals, including chlorofluorocarbons (CFCs), halons, and other ozone-depleting substances (ODS), have triggered the breakdown of these ozone molecules.
The Antarctic ozone hole is the most famous and most severe case of ozone depletion. Every year, the ozone layer above Antarctica becomes drastically thinner, usually reaching its maximum size in September or October. A combination of cold temperatures causes this seasonal phenomenon, polar stratospheric clouds (PSCs), and sunlight returning to the region after the long polar winter. This promotes chemical reactions that lead to the release of chlorine and bromine, which then destroy ozone.
In recent years, technological advancements have improved the monitoring of the ozone layer through the use of satellites. ESA’s Sentinel-5P Satellite and NASA’s Aura Satellite have launched advanced sensors to monitor ozone layer thickness, track ozone depletion, and assess recovery over time.