What are the characteristics of troposphere and stratosphere?

The earth where we live is surrounded by a thick atmosphere. The atmosphere is divided into several layers. The layer closest to us is called the troposphere, where human beings live. This layer has the highest air density and pressure. With the increase of height, the air pressure decreases gradually and the temperature decreases continuously. There is a lot of water vapor in the troposphere. When the ground air is heated, it will become hot air and flow upward, while the upper cold air will drop. Due to the rotation of the earth, the heating is uneven everywhere, and the air has to flow around, thus forming the wind. When water vapor meets cold at high altitude, it will form various meteorological changes such as rain, dew and lightning. The average height of the troposphere is 1 1 km, and early airplanes can only fly in this atmosphere.

The atmosphere above troposphere is called stratosphere. The temperature here is extremely low (about 56't2), there is no water vapor, and the temperature does not change with height. This layer is also called the stratosphere. Air has no upward motive force, and can only move horizontally. Apart from the wind, there are no weather phenomena such as clouds, rain, thunder and electricity. Because the plane uses a jet engine and a pressurized cockpit, it can fly in the stratosphere. The stratospheric air is thin and there is no weather change, which greatly reduces the flight resistance of the aircraft and makes it fly quickly and safely. The stratosphere altitude ranges from L 1 km to 80 km, the flying altitude of supersonic passenger aircraft is L3 ~ 18 km, and that of subsonic jet is 7 ~ 13 km. This is the boundary area between troposphere and stratosphere, sometimes called troposphere.