What is the stratosphere like?

The most striking feature of the stratosphere is that the atmosphere is dominated by advection and there is almost no vertical convection. This is mainly because the temperature structure of stratosphere and troposphere is different. From the tropopause to a height of about 35 kilometers above the ground, the atmospheric temperature in the stratosphere is very low, about -80O. From 35 kilometers to the top of the stratosphere, the temperature increases with height. Stratospheric temperature is low, the air is thin, and there is little water vapor.

Because the stratosphere is higher than the troposphere, the solar radiation in the stratosphere contains more short-wave ultraviolet radiation than the solar radiation reaching the surface. Generally speaking, ultraviolet light from the sun is divided into three regions according to wavelength, and ultraviolet light with a wavelength between 315-400 nm (1nm =10-9m) is called UV-A region. However, it will not cause damage to the surface biosphere. In fact, a small amount of ultraviolet light in this band is also necessary for surface organisms, which can promote the transformation of sterols into vitamin D. If it is lacking, it will cause rickets, which is especially unfavorable for children's development.