Q. Does thermal inversion occur in the winter or in the summer?
The Pollutant low altitude thermal inversion take place in the winter and in this period of the year the sun heats the soil less and the natural upward move of warm air decreases. Consequently the pollutants form a low altitude layer between the cold air layer near the ground and another layer of warmer air above. The pollutant layer over big urban concentrations or industrial areas reduces the penetration of the sun's energy and the air bellow takes an even longer time to warm.