In a scenario describing a thermal inversion, which location would show the highest pollutant concentration near the surface?

In a scenario describing a thermal inversion, which location would show the highest pollutant concentration near the surface?

• A. Location closest to the ground
• B. Location high in the atmosphere
• C. Location mid-altitude
• D. Location at the inversion layer top

Answer: (A)

Thermal inversions create a stable lid of warmer air above cooler air near the ground, which curtails vertical mixing. Emissions from sources at the surface get trapped beneath this lid and accumulate right at ground level because the air can’t rise to dilute them. So the highest pollutant concentrations occur near the surface. As you go higher, you’re above the inversion cap, where mixing is limited and there are fewer surface emissions contributing, leading to lower concentrations.

Thermal inversions create a stable lid of warmer air above cooler air near the ground, which curtails vertical mixing. Emissions from sources at the surface get trapped beneath this lid and accumulate right at ground level because the air can’t rise to dilute them. So the highest pollutant concentrations occur near the surface. As you go higher, you’re above the inversion cap, where mixing is limited and there are fewer surface emissions contributing, leading to lower concentrations.