What parameter is often changed in a dispersion model to assess its impact on air quality?

The parameter that is often changed in a dispersion model to assess its impact on air quality is the emission rates. This is because emission rates directly affect the concentration of pollutants in the atmosphere. By varying the amount of pollutants emitted from a source, researchers can evaluate how different levels of emissions influence air quality under various atmospheric conditions.

When emission rates are altered, the model can simulate how changes in pollution output can lead to different concentrations of contaminants in the air, enabling assessments of both short-term and long-term air quality impacts. This is crucial for regulatory compliance, health assessments, and the development of strategies to mitigate pollution effects on the environment and public health.

While wind speed, temperature, and humidity levels are also important parameters in dispersion models, they mainly influence the dispersion pattern and behavior of the pollutants rather than their initial concentrations in the atmosphere. Understanding the interplay between these factors is vital, but adjusting emission rates provides a direct link to how pollution levels can be managed and controlled.