User:R.Niruthia

= ATMOSPHERE = Atmosphere is the whole mass of air surrounding the earth. It is a thin layer that seals the planet and also protects it from the vacuum of the space.It also protects us from the electromagnetic radiations given off by the sun and also from the small objects flying the space such as meteroids.

Composition Of The Air In Atmosphere
Atmosphere is a mixture of gases were the two gases namely nitrogen (78%) and oxygen (21%) together constitute 99% of the whole air and the remaining 1% of it is shared by various gases namely argon(0.9%), carbon-dioxide(0.03%) and the rest share very small percentage of it. Our atmosphere also contains water vapour. In addition, Earth's atmosphere contains traces of dust particles, pollen, plant grains and other solid particles.

Structure Of Atmosphere
Our atmosphere is broken down into five different layers each with its own characteristics and properties. The layers namely are Troposphere, Stratosphere, Mesosphere, Thermosphere and exosphere.

Troposphere

 * Troposphere is a layer where mixing of gas takes place.
 * the temperature decreases with increasing altitude.


 * air that we breath is available here.


 * lowermost layer of atmosphere.
 * change in weather phenomena takes place here. as water vapour and dust particles are present here.
 * extends up to a height of 10km from the mean sea level.

Tropopause
It is thin that separates troposphere from stratosphere.It is in this layer that the mixing of gas stops.

Stratosphere

 * This is a very stable layer that support the flying of aeroplanes.
 * The Ozone layer is present is in this layer that protects us fro the harmful ultraviolet rays emitted by the sun.
 * here the temperature increases with increasing altitude.
 * it extends up to a height of 50 km from the mean sea level.

Stratosphere
It is layer that separates stratosphere from mesosphere.

Mesosphere.

 * the third layer of the atmosphere where the meteoroids get burnt upon their entry.
 * the temperature decreases with increasing altitude.
 * it extends up to a height of 80 km from the mean sea level.

Mesospause
it is a thin layer that separates mesosphere from thermosphere.

Thermosphere

 * the layer in which ionosphere is present.
 * the temperature increases with increasing altitude.
 * this layer is cloudless and also water vapour is not present.
 * this layer extends upto a height of 700 km from mean sea level.

Thermopause
It is a thin layer that separates thermosphere from exosphere.

Exosphere.

 * the outermost layer of the atmosphere.
 * this layer merges with the solar winds.