The temperature decreases when we go upwards to various heights from the surface in the troposphere, but due to certain special circumstances, the temperature increases instead of decreasing. Such a condition is called thermal inversion.
Conditions responsible for temperature inversion:
The conditions responsible for thermal inversion have been described as follows:
1. Dry air: When the vapor absorbs heat emitted from radiation from the earth and stop , heat from escaping. Because of the absence of this quality in the dry air, the earth cools down shortly.
2. Condition of glaciation: In the polar and glacial regions, there is rapid thermal irregularity evolving from the surface due to continuous negative radiation or cold wave distortion due to which inversion of temperature takes place rapidly.
3. Stable weather: In case of stable weather, the process of heat radiation takes place uninterrupted. In the absence of change in the weather, the same conditions remain for a long time. Therefore, there is no interference in thermal inversion.
4. Cold and long nights: Nights are longer in winter. Cold waves are radiated in place of heat waves from the surface of the earth in the last phase of such nights. Due to this, cold waves develop in place of hot waves from the surface of the earth. Due to this, the temperature of the layers which are in contact with such surfaces decrease rapidly, while the temperature of the layers present above it remains higher.
5. Clear sky: The radiations coming out of the earth at the night time return upon colliding with the clouds, so that the earth does not cool down. This heat does not return to the earth in a clear sky, which causes the earth’s surface to cool quickly and the possibility of thermal inversion increases.
6. Steady air: The continuous blowing of winds prevent the temperature of a particular place from falling. In winter, the effect of coldness can spread to lower layers, due to the calmness of wind and clearness of the sky, in the long nights, thus causing thermal inversion.
7. Shielded valleys: In deep valleys with more steep slopes, the cool air is accumulated down with intensity. Due to this, thermal inversion is caused.
8. Entry of cold air zone: When the cold air zone pushes up a hot air zone, the situation of thermal inversion is created.
