Effects of troposphere and stratosphere on flight.

Aircraft can not only fly in the stratosphere, but also fly in the stratosphere more safely.

The atmosphere closest to the ground is called the troposphere. Because the energy contained in this atmosphere mainly comes from absorbing long-wave radiation from the ground, the farther away from the ground, the lower the temperature. In daily life, the temperature in the mountains is lower than that in the mountains, which is the reason.

In the troposphere, the temperature near the ground is high, and the gas is easy to expand and rise when heated, while the temperature in the upper air is low, and the gas is easy to contract when it is cold, so the circulating air convection movement is produced (this is the origin of the troposphere name). The temperature of the air near the ground becomes lower in the process of rising, and the water vapor contained in it condenses when it is cold, which is easy to form clouds and cause rainfall.

Therefore, the troposphere is full of airflow and the weather conditions are complex, so it is not a very suitable airflow layer for flight.

On the contrary, in the stratosphere above the troposphere, its energy mainly comes from the absorption of solar ultraviolet by ozone. So the farther away from the ground, that is, the closer to the sun, the higher the temperature of the air. That is to say, in the stratosphere, the temperature change is just the opposite of that in the troposphere: the higher the altitude, the higher the temperature. The gas with higher temperature is lighter and above it; The gas with lower temperature is heavier, below. This is a relatively stable state. So in the stratosphere, there is little convection up and down, and the airflow is mainly horizontal, which is the origin of the stratosphere name.

It is precisely because there is less convection in the stratosphere and the higher the temperature, the water vapor in the updraft will not condense when it is cold. So the stratosphere is always sunny, partly cloudy and with high visibility. In addition, there is little airflow moving up and down, so it is not easy for the plane to bump when flying in it. So modern flights always climb higher and higher after taking off, and they don't start flying horizontally until they cross the troposphere and enter the stratosphere.