Atmospheric composition refers to the makeup or constitution of Earth's atmosphere. It includes information about the different gases, aerosols and other components present in the air we breathe. The primary atmospheric gases include nitrogen (78%), oxygen (21%) and trace amounts of other gases such as argon, carbon dioxide, methane and water vapor.
The composition of the atmosphere can vary depending on location, altitude, weather conditions, seasonal changes or human activities that release pollutants into the air. For example, higher concentrations of ozone may be found in certain areas at different times of year due to increased sunlight exposure while urban areas may have higher levels of carbon monoxide and other pollutants from vehicle emissions and industrial activity.
Understanding atmospheric composition is important for scientists studying climate change, weather patterns or air quality as well as for policymakers developing strategies to mitigate the impacts of human activities on our planet's atmosphere.