சர்வம் பிரும்ம மையம்
- The entire Universe (Chemical constituents) is the property of GOD until it ceases to exists, as per his wish and will, and until he reconstitutes it according to his own scientific laws. Hence, we his devotees are his ever ultimate properties.
- One may keep on listing the requirements of life. The decreasing order of priority is air, water, food, cloths, residence and so on. Air will find its place in the list and that too in the first place only when the listing is done carefully.
- If someone travels out, he/she enquires more about the availability of transport, food , other such related matters and facilities in & around that place, but never thinks of air.
- Fish live in an atmosphere of water molecules; where as we and all other animals live in an atmosphere of gas molecules. Therefore, one can imagine the amount of gift from GOD and the fate of life on the surface of the earth if all gas molecules escape out of earth.
- We can live without food for days ; but not without air even for a minute (most of the time, even during day time, we are not aware that we are breathing)
- Hence, the atmosphere is a common property which everyone can enjoy but no one should misuse it by way of pollution, since it also belongs to others.
- We should not only have good atmosphere in family, friends circle, works spot etc., for good dealing, but also a good atmosphere of air for healthy life.
- We have already started buying water, hope the time will not come for buying air, the basic requirement for life.
- An average human being consumes three cylinders of air each day. Based on the present market rates of compressed air supplied for technical purposes, this amounts to an approximate cost of Rs 16, 00,000 per year and about Rs.10 core for an average age of 65 years, during the period of which one may acquire properties equivalent to such amount. But, in that case it means using public property of air to live to acquire personal properties.
- According to Yoga Sasthra , proper breathing (as in the case of Pranayama) will lead to a healthier and longer life
- Plants play major role for ecological balance, by taking carbon dioxide for photosynthesis liberating oxygen during day time and consuming oxygen to let-out carbon dioxide during night while breathing.
- But, we always take oxygen and let out carbon dioxide all time
- One cannot take many things without giving anything. According to the law nature, if one takes something from anything he/she has to return an equivalent thing to it.
- Hence, every individual, as a consumer of the nature, must also act as a contributor to the nature and the society in some way or other, as done by several saints, scientists, teachers, administrators, social workers etc.
- One can live,on the earth which itself is common ,in a separate country, place, house ; but not in a separate atmosphere.
- Therefore, as a typical example, every one is in unison with the Universe, the Brummam,பிரும்மம்(i.e., சர்வம் பிரும்ம மையம்)
THE ATMOSPHERE OF THE EARTH’S CAN BE DIVIDED INTO FIVE MAIN LAYERS: FROM THE LOWEST TO HIGHEST (1 TO 5), THE FIVE LAYERS ARE:
- Troposphere (≤ 12 km ; N2, O2, Ar, CO2, H2O)
The troposphere contains roughly 80% of the mass of Earth’s atmosphere. The troposphere is denser than all its overlying atmospheric layers because a larger atmospheric weight sits on top of the troposphere and causes it to be most severely compressed. Fifty percent of the total mass of the atmosphere is located in the lower 5.6 km of the troposphere. It is primarily composed of nitrogen (78.09%), oxygen (21%), argon (0.93%), carbon dioxide (0.039%) , with small concentrations of other trace gases by volume amounting to total mass about 5.15×1018kg.
Nearly, all atmospheric water vapor (moisture) is found in the troposphere, so it is the layer where most of Earth’s weather takes place. It has basically all the weather-associated cloud generated by active wind circulation. Most conventional aviation activity takes place in the troposphere, and it is the only layer that can be accessed by propeller-driven aircraft.
Fig-1: Different layers of the atmosphere
- Stratosphere (12-50 km ; N2, O2, O3)
The stratosphere is layered in temperature because ozone (O3) absorbs high energy UV energy from the Sun and is broken down into atomic oxygen (O) and diatomic oxygen (O2). Atomic oxygen is prevalent in the upper stratosphere due to the bombardment of UV light and the destruction of both ozone and diatomic oxygen. The mid stratosphere has less UV light passing through it, O and O2 combine to produce natural ozone.
It contains high concentrations of ozone, which is the part of Earth’s atmosphere. The stratosphere defines a layer in which temperatures rise with increasing altitude. This rise in temperature is caused by the absorption of ultraviolet (UV) radiation from the Sun by the ozone layer. Although the temperature may be −60 °C, the top of the stratosphere is much warmer, and may be near 0 °C. This is the highest layer that can be accessed by jet-powered aircraft.
Fig-2: Human activity in the atmospheric layers
Airliners cruise at altitudes of 9–12 km in the lower stratosphere. This optimizes fuel burn, due to the low temperatures encountered. It allows the airliner to fly faster for the same amount of drag. It also allows them to stay above hard weather extreme turbulence.
Human activity in the Troposphere and ozone depletion in Stratosphere
Some activity on the earth (Troposphere) leads to decline of ozone in Earth’s stratosphere, and a much larger decrease in stratospheric ozone around Earth’s polar regions. The latter phenomenon is referred to as the ozone hole.
Ozone depleting substances(ODS):
Chlorofluorocarbons (CFCs)
Carbon tetrachloride (CCl4),
Methyl chloroform (CH3CCl3)
Hydrobromofluorocarbons (HBFCs)
Hydrochlorofluorocarbons (HCFCs)
Methyl bromide (CH3Br)
Bromochloromethane (CH2BrCl)
The polar ozone hole formation is due to catalytic destruction of ozone by atomic halogens. The main source of these halogen atoms in the stratosphere is photo dissociation of man-made halocarbon refrigerants, solvents, propellants, and foam-blowing agents (CFCs, freons, halons). These compounds are transported into the stratosphere by winds after being emitted at the surface. Halogen atom decompose ozone as follows
Cl2 + UV light → 2Cl
Cl+O3 → ClO+O2
ClO+O → Cl+O2
O3+O → 2O2
CFCs and other contributory substances are referred to as ozone depleting substances (ODS). The ozone layer prevents most harmful UVB wavelengths (290–320 nm; UVA:400-320nm) of ultraviolet (UV) light from passing through the Earth’s atmosphere.The CFC’s involve in the destruction of ozone as follows:
Step-1: Photolysis of CFC’s
Cl2CF2 + UV light → ClCF2 + Cl
Step-2: Catalytic destruction of ozone
Cl + O3 → ClO + O2
ClO + O3 → Cl + 2O2
The decrease in ozone is a worldwide concern, leading to adoption of the protocol that bans the production of CFCs, halogens, and other ozone-depleting chemicals such as carbon tetrachloride and trichloroethane.Variety of biological consequences may result from the increased UV exposure due to ozone depletion.
- Mesosphere (50 to 80 km)
The mesosphere is poorly studied, compared to the stratosphere, (which can be accessed with high-altitude balloons) and the thermosphere in which satellites can orbit.
The mesosphere is hard to study. Weather balloons and jet planes cannot fly high enough to reach the mesosphere. The orbits of satellites are above the mesosphere. Hence, there are not many ways to get scientific instruments in the mesosphere.
The mesosphere is also the layer in which a lot of meteors burn up while entering the Earth’s atmosphere. From the Earth they are seen as shooting stars.
- Thermosphere (80 to 700 km; O, N, He)
Atomic oxygen (O), atomic nitrogen (N), and helium (He) are the main components of air in the upper thermosphere.
This atmospheric layer undergoes gradual increase in temperature with height. Unlike the stratosphere, wherein a temperature inversion is due to the absorption of radiation by ozone, the inversion in the thermosphere occurs due to the extremely low concentrations of molecules. The temperature of this layer can rise as high as 1500 °C.
- Exosphere (700 to 10,000 km; H2, He, N2, O2, CO2)
This layer is mainly composed of extremely low concentrations of hydrogen, helium, nitrogen, oxygen and carbon dioxide. The atoms and molecules are so far apart that they can travel hundreds of kilometers without colliding with one another.
Even though, we live in troposphere, the lowest part of atmosphere, other upper spheres are also equally important as they are interrelated.
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(i) Please go back to CONTENTS for all the Articles in PoC:
https://dradchem.wordpress.com/2015/06/22/properties-of-chemistry-poc-contents-2/
(ii) Please refer the Articles in HRE-51 regarding the Earth
https://drdayalan.wordpress.com/2016/11/18/hre-51
(iii) Also, please click below to go to CONTENTS for Articles in HRE:
https://drdayalan.wordpress.com/2015/06/01/hre-contents-hindu-religious-extracts-prof-dr-a-dayalan/