Simulation of Surface Ozone

Ozone (O3) is a highly reactive gas that is photochemically produced in the atmosphere. In the stratosphere, it absorbs ultraviolet radiation and protects life on Earth. Close to the surface, however, ozone is a potent pollutant that is harmful to both humans and the environment. This animation shows the amount (concentration) of ozone in the atmosphere at the surface of Earth, as represented by the GEOS composition forecast system (GEOS-CF) for the time period July 22 – August 10 2018. High concentrations of ozone are depicted in white while low concentrations are shown in dark blue. As shown in the simulation, surface ozone exhibits a strong change through the day (diurnal cycle). It is formed in the daytime, under the influence of sunlight, through chemical reactions of nitrogen oxides and volatile organic compounds. The highest concentrations are found in the afternoon in the vicinity of urban areas, a consequence of human activities releasing nitrogen oxides and other pollutants, and in other polluted regions, such as around wildfires.