How does a temperature inversion worsen air pollution?
A temperature inversion occurs when air warms with height through a layer, capping cooler air below.
Formation process and geographic mechanism
On clear calm nights the ground cools rapidly, chilling adjacent dense air that can drain into valleys. Warmer air above suppresses vertical mixing. Particles from traffic, heating and industry then accumulate in a smaller volume. An inversion does not create pollution but raises concentration by blocking dispersion.
Spatial outcomes, measurement and management
Surface heating or strong wind can break the layer, while winter high pressure may maintain it for days. Valley shape, source position and inversion height alter exposure. Air-quality alerts work with emission reduction, public transport and protection of vulnerable groups. Fog and inversion are not identical but may coexist under calm cold conditions.