Answer:
Normally, cool air near earth's surface expands and rises, carrying pollutants higher into the troposphere.
Explanation:
Thermal inversion is an atmospheric phenomenon. It tends to occur in large urban centers where industrial production is intense and the amount of polluting gases is greater. When the thermal inversion happens, the cold air is trapped and is prevented from circulating. This cold air is trapped close to the Earth's surface, very close to the toposphere. The problem is that cold air is loaded with polluting gases and this promotes strong atmospheric pollution, which aggravates many environmental and health problems. It is because of the thermal inversion that we can see a gray layer on the horizon of some urban centers.
