Let us now understand about the Troposphere and Tropopause. As we had said, the lowest layer is called the troposphere. This layer is closest to the earth. The main characteristic of this layer is the decrease in temperature with height.
Where the temperature no longer decreases with height defines the upper part of the troposphere. This upper boundary is called the tropopause. In the tropopause, the temperature remains constant with increase in altitude.
The height of the tropopause is not constant across the earth. Over the equator, tropopause is found at approximately 16 kilometres with an average temperature of -70 degrees. This is called as the Equatorial Tropopause.
Over the poles, the height of the tropopause is just about 8 kilometres with a temperature of -50 degrees. This called as the Polar Tropopause. The average height of tropopause is taken as 11 kilometres, which is found at about 45 degrees latitude.
You can see that the temperature of tropopause is lower at the equator as compared to the poles. This is the reverse of what happens at the surface, where the surface temperature is lower at the poles as compared to the equator.
This is because the height of tropopause is more at the equator than at the poles. We can say that the height of tropopause reduces with latitude, while the temperature of tropopause increases with latitude.
In the troposphere, under normal circumstances, the temperature falls with height. However, in certain places you may find that the temperature may remain constant with height, resulting in an isothermal layer. In certain other places you may find that the temperature increases with height, resulting in an inversion layer.
Understanding troposphere and troposphere is important for pilots because most of the passenger aircraft fly in the troposphere. In addition, most of the weather phenomena are also found in the troposphere.
The height of tropopause is important for pilots because you can find the presence of Jet Streams and Clear Air Turbulence (CAT) near the tropopause.
The tropopause signifies the start of a marked temperature inversion. This effectively limits the vertical movement of air and clouds within our atmosphere. It’s useful to know then, that the tropopause usually signifies the limit of cloud development.