The lower part of the atmosphere, called the troposphere, contains about 4/5 of the entire mass of air, which consists of nitrogen (78%), oxygen (21%), argon (less than 1%) and carbon dioxide (0.03%).Other gases such as helium, hydrogen, neon, krypton, and ozone, make up a few thousandths of a percent.
height of the troposphere - about 10-15 km, the temperature here drops by an average of 0,6 ° C per 100 m. This layer is almost all the water vapor and clouds are formed almost all.Turbulence most strongly developed near the surface, as well as jet streams upper troposphere.
air pressure at the upper boundary of the troposphere in 5-8 times less than at the bottom.In this layer are processes
crucial to the formation of climate and weather on the Earth's surface.Over different latitudes the height of the troposphere varies, over the equator - about 15 km over the poles - 9 km, and in temperate latitudes - 10-12 km.
stratosphere is above the troposphere, the layer of transition between the two is called the tropopause.The stratosphere extends up to 50-55 km above the Earth's surface temperature is increasing with altitude.This layer of water vapor is negligible, but at an altitude of 20-25 km are sometimes observed nacreous clouds, composed of supercooled water droplets.It contains atmospheric ozone and temperature rise due to its absorption of solar radiation.
Above the stratosphere is the mesosphere layer and extends to about 80 km.In it the temperature drops from a height of several tens of degrees below zero, resulting in highly developed turbulence.The upper boundary layer of air pressure is 200 times smaller than the surface of the Earth.
In the troposphere, stratosphere and mesosphere holds about 99.5% of the mass of air in the upper layers is only a tiny amount of it.Above the mesosphere is the thermosphere, which is characterized by very high temperatures.It is divided into two layers: the ionosphere, which extends to a height of about a thousand kilometers, and the exosphere, which passes into the earth's crown.
ion content in the ionosphere is many times greater than in the lower layers, they are charged atoms of oxygen and nitric oxide molecules are present as free electrons.The temperature here is very high, approximately 800 km from the Earth's surface, it reaches 1000 ° C.
exosphere ends with the Earth's atmosphere at an altitude of 2,000-3,000 km, where the hydrogen forms the Earth's crown, which extends more than 20 000 km.The gas density is negligible, 1 cu.see there are only about 1,000 particles.
- Biofayl, atmosphere and its structure