Atmospheric Structure and Ozone

According to NASA, the gases in Earth's atmosphere include: Nitrogen — 78 percent. Oxygen — 21 percent. Argon — 0.93 percent.

Troposphere is considered as the most important layer of atmosphere. It is the lower most layer of the Atmosphere. Its average height is 13 km. The thickness varies from 8 km to 18 km, with maximum at equator and minimum poles. All the atmospheric phenomena such as rains, wind, clouds, etc. take place in this layer. Troposphere contains roughly 80% of the mass of Earth's atmosphere and it composed of composed of nitrogen (78%) and life giving gas oxygen (21%) with small concentrations of other trace gases. Hence, Troposphere is very important for the existence of life on earth as it causes the cloud formation, raining and maintaining the heat balance of the earth.

Troposphere,

The layer present between stratosphere and thermosphere is mesosphere. Height of mesosphere layer is 80-85 kms. It is the layer present between stratosphere and thermosphere. In the mesosphere, temperature decreases as the altitude increases. The upper boundary of the mesosphere is the mesopause, which is the coldest naturally occurring place on Earth.

The atmospheric layer that supports life is called troposphere. It is the lowest layer of earth’s atmosphere. The troposphere starts at Earth's surface and goes up to a height of 7 Km to 16 km. Almost all weather phenomenon occur in this layer.  

Commercial jet aircraft fly in the lower stratosphere to avoid the turbulence which is common in the troposphere below. The stratosphere is very dry; air there contains little water vapor. Because of this, few clouds are found in this layer; almost all clouds occur in the lower, more humid troposphere.

• The stratosphere and mesosphere together are sometimes referred to as middle atmosphere.
  
• The layer present between stratosphere and thermosphere is mesosphere. Height of mesosphere layer is 80-85 kms. In the mesosphere, temperature decreases as the altitude increases. The upper boundary of the mesosphere is the mesopause, which is the coldest naturally occurring place on Earth.
• Ozonosphere is also called as stratosphere which consists of ozone gases that prevents UV rays from entering the earth’s surface.
  

The layer of earth above mesosphere is thermosphere. It consists of ions due to ultra violet radiations causing photo ionization and hence forms ionosphere.  The temperature in this zone increases with increase in altitude.

Ionosphere lies beyond the ozonosphere at height of about 60 km above the earth's surface. In this layer temperature again starts rising with altitude. Here density of air is very low and the gases present is very small.  At this level ionization of atmosphere begins to occur by the impact of cosmic rays. Radio waves transmitted from the earth are reflected back to the earth from this layer.  

The layer of the atmosphere near the surface of the earth or the lowermost one is called troposphere. The average thickness of this layer is about 14 km. Most of the weather forming phenomena occure in this layer.

Stratosphere

The Ozone layer is mainly found in the lower portion of the stratosphere, from approximately 15 to 35 kilometers (9.3 to 21.7 mi) above Earth. The ozone layer absorbs 97 to 99 percent of the Sun's medium-frequency ultraviolet light.

The tropopause is the boundary region between the troposphere and the stratosphere. Measuring the temperature change with height through the troposphere and the stratosphere identifies the location of the tropopause. In the troposphere, temperature decreases with altitude.

Clouds have a very high albedo, reflecting a significant portion of incoming solar radiation back into space, which accounts for the difference between the Earth's surface albedo and the planetary albedo.

The thermosphere is the layer where gas molecules are sparse and absorb high-energy solar radiation, resulting in very high kinetic energy (high temperatures).