Did you know? Out of the variety of planets in the solar system, the earth is the only planet with an atmosphere, which can sustain life. In this description, we’ll read about the composition of the earth’s atmosphere. The early Greeks took ‘air’ as one of the four elementary substances, along with earth, fire, water, and the air itself. These together formed the fundamental component of the universe. After years of study, John Dalton, by the early 1800s, recognized that the atmosphere was an envelope of several chemically distinct gases, which are in a relative amount in the lower atmosphere. On discerning, he determined the major components to be nitrogen, oxygen, and a combustible substance, which was later shown as argon.
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Components of Earth’s Atmosphere
Earth’s atmosphere forms an envelope on it, which contains various gases in different compositions. The prime task of these gases is to enable respiration, protect from the sun’s harmful U.V. rays, etc. Now, the chief components of the earth’s atmosphere include two main portions – Constant Components and Variable Components.
Constant Components
These are the components of the earth’s atmosphere whose proportions remain the same over time and location.
| Nitrogen (N2) | 78.08% |
| Oxygen (O2) | 20.95% |
| Argon (Ar) | 0.93% |
| Neon, Helium, Krypton | 0.0001% |
Variable Components
These are the components of the earth’s atmosphere whose proportions vary over time and location.
| Carbon dioxide (CO2) | 0.038% |
| Water vapor (H2O) | 0-4% |
| Methane (CH4) | trace |
| Sulfur dioxide (SO2) | trace |
| Ozone (O3) | trace |
| Nitrogen oxides (NO, NO2, N20) | trace |
Some Interesting Atmospheric Facts
Now that the components of the earth’s atmosphere are clear and distinct with their proportions, here are some interesting atmospheric facts that might amaze you.
- The early pioneers of aerology were scientists such as Richard Assmann and Leon Teisserenc de Bort.
- The troposphere is the closest layer to the earth’s surface. The other layers beyond the atmosphere include the stratosphere, the ozone layer, the mesosphere, and the thermosphere.
- The major earth’s atmospheric components include smoke, toxic gases, dust, ash from volcanoes, and salt.
- The troposphere carries almost 80% weight of the atmosphere.
- This layer is the thinnest and reaches approximately 12km from the earth’s surface.
- The mesosphere extends between 50 and 70km from the earth’s surface.
- The thermosphere contains only 0.001% of the gases in the atmosphere.
