The atmosphere is a layer formed by argon, helium, carbon dioxide, ozone, water vapor and, mainly, by nitrogen and oxygen. This layer is of fundamental importance for the maintenance of life on Earth, because, in addition to containing oxygen, it protects us from ultraviolet rays.
There are different classifications of the layers of the atmosphere, each based on a specific criterion. One of these classifications analyzes the composition of air, dividing the atmosphere into a homosphere (composition without major variations); heterosphere (large amounts of helium and hydrogen) and exosphere (extremely thin layer, where gaseous molecules begin to escape Earth's gravitational attraction).
The most used classification has as a determining factor the temperature variation in the Earth's atmosphere. According to this division, we have five distinct layers:
Atmosphere layers
Troposphere: it is the layer that extends from the terrestrial soil (sea level) until reaching 12 kilometers of altitude. As altitude rises, the temperature decreases, reaching -60 °C at the highest point. In this layer, the formation of clouds and rain occurs.
Stratosphere: is the layer above the troposphere, reaching up to 50 kilometers above sea level. The temperature ranges from -5 °C to -60 °C. This region of the atmosphere houses the ozone layer, which protects us from ultraviolet radiation, which, in large amounts, is extremely harmful to life on Earth.
Mesosphere: extends from the end of the stratosphere to 80 kilometers above sea level. The temperature ranges from -5 °C to -95 °C, being considered the coldest layer of the atmosphere.
Thermosphere: is the layer above the mesosphere, reaching 500 kilometers in altitude. It registers the highest temperatures in the atmosphere, reaching up to 1,000 °C. This characteristic is due to the large concentration of atomic oxygen, responsible for the absorption of solar energy.
Exosphere: starts at the end of the thermosphere and extends into space.
By Wagner de Cerqueira and Francisco
Graduated in Geography
