Inversion of Temperature

Inversion of temperature is a turnaround of the normal behaviour of temperature in the troposphere. This is a meteorological phenomenon. It is also termed thermal inversion.

Importance of Inversion

They play a crucial role in understanding cloud forms, visibility and precipitation. An inversion acts as a shield for the warm air rising from the earth’s surface. Hence, the spreading of dust, smoke and other air pollutants is limited. In areas where inversion is low, convective clouds cannot grow, resulting in less precipitation. Inversion also results in low visibility as the air near the surface gets cold, causing fog.

Types of Temperature Inversions

There are four types of temperature inversions:

Ground inversion: It happens when the warm air gets cooled by contacting a cold surface. The cooling occurs until the warm air gets cooler than the atmosphere above it. This inversion occurs at night. On a clear night, the surface cools at a rapid rate. When the temperature falls below the dew point, we experience fog. The air forms a thick layer above the ground if the land is mountainous.

Turbulence inversion: This type of inversion of temperature is witnessed when a layer of calm air lies above moving air. This moving air is also called turbulent air. Vertical mixing occurs in the turbulent layer that brings warm air down and cools it. It only cools the upper part of the turbulent layer. Hence, the layer of clam air above remains warmer, causing inversion.

Subsidence inversion: This type of inversion takes place when an extensive layer of air descends. This layer gets compressed and heated due to atmospheric pressure. In this inversion of temperature, the lapse rate is reduced. The lapse rate means the rate at which the temperature descends with an increasing height. This type of inversion occurs in the northern continents during winter because they are located under large high-pressure centres.

Frontal inversion: This inversion occurs when cold air crosses warm air. This cold air lifts the warm air. Hence, the cold air goes underneath the warm air. The slope of the inversion of temperature is horizontal.

Causes of Inversion of Temperature

Under normal conditions, air flows from warm to cool areas. Throughout inversion of temperature, the temperature increases with increasing height. The warm air acts as a shield and prevents the mixing of atmospheric pollutants. These layers are called stable air masses.

Inversion of temperature can happen when the air near the surface loses heat. This happens during the night. It can also occur in coastal areas. The cold water near the land can decrease the temperature of the land. Therefore, the cold air layer stays under the warm air layer.

Inversion of temperature can occur in mountains and valleys. The cold air near the mountains can flow through the valleys. This cold air pushes the warmer air up, thus going under the warm air. In snowy areas, the air above the snow is warmer, causing temperature inversion.

Consequences of Temperature Inversion

The most common disadvantage of temperature inversion is the extreme conditions it creates. Freezing rain occurs due to temperature inversions. It can also cause ice storms. Inversion of temperature releases a lot of energy around it. This can cause thunderstorms and tornadoes.

Conclusion

Inversion of temperatures causes the formation of clouds, precipitation, and frost. This is due to the condensation of warm air. The inversion of temperature is protection to human beings. The dry air of the inversion catches the air pollutants towards itself. Because of the inversion of temperature, air pollutants such as dust particles and smoke do not scatter on the land. This shield acts as a cover to the nearest atmospheric sphere (troposphere).