Effects of Nitrogen and Oxygen on Tropospheric Temperature
1, troposphere definition: the lowest layer of the atmosphere, with the thickness (8 ~ 17 km) varying with seasons and latitudes, and the average temperature drop rate is 6.5℃/ km with the height increasing, with convection and turbulence. Weather phenomena and weather processes mainly occur in this layer.
2. Location: Located at the bottom of the atmosphere, it extends from the earth's surface to the top of the troposphere, which is the starting point of the stratosphere. The average thickness is about 12km, and its thickness varies from 8km above the poles of the earth to 17km above the equator. It is the densest layer in the atmosphere, where about 75% of the air quality and more than 90% of the water vapor quality are concentrated.
The lower bound is connected with the ground, and the height of the upper bound varies with geographical latitude and season. Its height varies with latitude, with the average height at low latitude 17 ~ 18km, mid latitude 10 ~ 12km and high latitude 8 ~ 9km, which is higher in summer than in winter.
At high latitudes, the friction of the surface will affect the airflow, forming a planetary boundary layer with an average thickness of 2 kilometers. The formation of this layer mainly depends on the topography, and it will also be separated from the rest of the troposphere by the countercurrent layer.
3. Features: The temperature decreases with the increase of height, because this layer can not directly absorb the short-wave radiation of the sun, but can absorb the long-wave radiation reflected from the ground and heat the atmosphere from the underlying surface. So the air near the ground is heated more, and the air far from the ground is heated less. With every increase of 1 km, the temperature drops by about 6.5 degrees.
Air convection, because the surface of lithosphere and hydrosphere is heated by the sun, the lower air is heated by thermal radiation, and vertical convection occurs between cold and hot air. Moreover, because the ground is divided into land and ocean, the temperature in different regions is different day and night and latitude, which forms the horizontal movement of air.
The horizontal distribution of temperature, humidity and other factors is uneven. When the atmosphere touches the ground, water vapor, dust, microorganisms and toxic substances produced by human activities enter the air layer. Therefore, in addition to the vertical and horizontal movement of airflow, the chemical process in this layer is very active. As the air mass gets cold or hot, water vapor forms a series of weather phenomena such as rain, snow, hail, frost, dew, clouds and fog.
4. Expansion: Because the troposphere is the most turbulent layer in the atmosphere, most passenger planes will fly over the top of this layer (that is, the tropopause) to avoid the airflow that affects flight safety.