Why is the temperature in the troposphere so hot at the bottom and cold at the top?

Because atmospheric temperature decreases with altitude, especially in the troposphere. However, under certain weather conditions, the atmospheric structure above the ground will experience an abnormal phenomenon in which the temperature increases with height. This is called "temperature inversion" in meteorology, and the layer of the atmosphere where the temperature inversion occurs is called the "inversion layer." .

In the troposphere, the general situation of vertical distribution of temperature is that it decreases with increasing altitude. For every 100 meters of elevation, the temperature decreases by 0.6°C. However, under certain conditions, the temperature in the troposphere may also rise with height, or the cooling rate on the ground may be less than 0.6°C/100 m as height increases. This phenomenon is called temperature inversion.