COMPOSITION OF ATMOSPHERE

ATMOSPHERE

Atmosphere is a blanket of gases and contains huge number of solid and liquid collectively called aerosols surrounding the earth from all sides and forms a protective boundary between the outer space and bio-sphere.

An interesting fact about the atmosphere is that density decreases rapidly with altitude. Nearly 99% of the air lies within 30 km of the earth’s surface.

The atmosphere also shields us from the sun’s ultraviolet radiations which are very harmful for plants and animals. Weather and climate is not possible without the presence of atmosphere. It acts transparent to the sun’s short waves radiation and opaque to the long waves radiation which the earth reflects during night. Thus, it maintains the proper heat balance on the earth. Radio communication is not possible without atmosphere. It also helps in the airways transportation which is consider the fastest means of transportations.

ATMOSPHERIC COMPOSITION

It is also called atmospheric chemistry. The entire atmosphere consists of a mixture of gases. These gases governed by Gas Law. Some of the particles in the atmosphere is the atmospheric single atom-, argon, helium and other are the molecules consisting of atoms of two or more than like- water vapour.

The study of atmosphere included many gases. The study of gases began with the work of element in the 17th century. The first gas a study in detail is CO2. It discovered in 1752. There is only small amount of CO2 in the atmosphere.

Our atmosphere constitutes the main following elements, these are as-

• Gases
• Water vapour
• Dust particles

GASES:- 

The principle gases of our atmosphere are as below;

Nitrogen; Nitrogen constitutes the major portion among the atmospheric gases. It is discovered by Rutherford in 1772 and initial name was Mephietic air.

There are following main characteristics of the nitrogen as under;

• This gas accounts 78.08% of the total volume of the atmosphere.

• It does not easily enter into chemical union with other elements but it is important constituent of many organic compounds.

• Its main function in the atmosphere is to regulate combustion by diluting oxygen.

• This gas has no colour, taste and its avoid quick burning.

• It extent for over 100 km from the earth surface.

• It is very important gas for human and most of the plants and animals as it general proteins which is very essential for their nature growth.

• Nitrogen is also important for the industrial and commercial view point also.

Oxygen; Oxygen happen to be the most important gas among the all gases because of its following characteristics;

• It is called life giver gas. It is very essential for respiration of human being, animals and plants. No life is possible without oxygen.

• When any substance burns O2 is consumed.

• It extends up to 120 km in the earth’s atmosphere but its main concentration is found up to 16 km.

• It is concentrate in our atmosphere is nearly 20.94%.

• This gas was first discovered by Joseph Priestley and its initial name was Dephlogistated air.

Carbon-dioxide; CO2 is the third important gas in our atmosphere.

• it is concentrate is nearly 0.03%

• it is very important gas for the process of photosynthesis by which the green plants make their own food.

• It is meteorologically important also because it is transparent to the incoming solar radiation.

• It is keep the air warmer near the ground and along with water vapour is largely responsible for greenhouse effect of the atmosphere.

• This gas discovered by Jean.

WATER VAPOUR:-

• The visible amount of water in our atmosphere is called water vapour.

• The amount of water vapour content of air may vary from 0.02% by volume in a cold dry climate to nearly 4% in the humid tropics.

• The most important think about water vapour is that 90% of it lies below 6 km and 50% of it lies below 2 km of the atmosphere.

• The main sources of water vapour in our atmosphere are the oceans, rivers, lakes, ponds, transpiration of plants etc.

• At the equator and tropics the concentration of water vapour is more but as we move toward the poles its concentration decreases.

Significance of water vapour:-

Water vapour is the source of all clouds and precipitation, like CO2, water vapour plays a significance role in the insolation action of the atmosphere in addition but also a part of the incoming solar radiation. Thus, it is an important control in regulating the energy transfer through the atmosphere.

DUST PARTICLES:-

When air below as winds with sufficient speed. It carried large quantities of particles and keep them suspends in the lower layers of the atmosphere. They are derived from the different sources like smoke, agricultural activities, volcanic activities, mining, meteors, transportation forest fire etc.

Sky looks blue due to presence of dust particles in the atmosphere which scattering the blue light.