What exactly does the term "atmosphere" imply?
The atmosphere is a thick gaseous envelope that wraps around the world on all sides like a blanket. It is tightly tied to the earth due to its gravitational pull, and it also contains life-giving gases such as oxygen and carbon dioxide.
The majority of the atmosphere is made up of gases, water vapour, and particles.
Gases in Earth's Atmosphere
The earth's atmosphere contains nitrogen (78.08%), oxygen (20.95%), argon (0.93%), carbon dioxide (0.04%), neon, helium, ozone, hydrogen, and other gases.
The ozone gas is observed in extremely small concentrations at a height of 20-25 kilometres and filters the incoming solar energy, preventing ultraviolet rays from reaching the earth.
Carbon dioxide is a greenhouse gas that helps maintain an average temperature of about 15 degrees around the globe.
Water Vapour In Atmosphere
Depending on the region, the amount of water vapour in the atmosphere ranges from 0% to 4% by volume. Water vapour diminishes from the equator to the poles as the temperature drops. The tropical zone (4%) has the highest percentage, whereas polar or desert locations have the lowest rate (1 per cent).
The volume of water vapour decreases as one rise in altitude. All precipitation and condensation events, such as clouds, fogs, dew, rainfall, frost, and snowfall, are caused by the moisture content of the atmosphere.
What is particulate matter, and what effect does it have on the environment?
These are small solid particles in the atmosphere that include dust, salt, pollen, smoke-soot, volcanic ash, and others. It is found in the troposphere or the lowest part of the atmosphere.
The beautiful colours seen at sunrise and sunset are due to the scattering of solar radiation by these particles. The blue colour of the sky is due to dust particles scattering.
STRUCTURE OF THE ATMOSPHERE
Although the precise boundary of the atmosphere is unclear, it is usually assumed to be roughly 1600 kilometres above the earth's surface. The structure of the atmosphere can be split into five tiers based on pressure and air temperature.
Troposphere
Stratosphere
Mesosphere
Thermosphere
Exosphere
Troposphere
It is the first and the lowest layer of the atmosphere comprising around 75% earth's atmospheric mass. The word troposphere comprises 2 words 'tropos; meaning rotation and 'sphaira' meaning sphere essentially describing the rotation turbulence that affects the flow of gases in this region.
With an altitude of roughly 8 km at the poles and 18 km at the equator, it is positioned between the earth's surface and the upper atmosphere. The thickness is greater at the equator because warm air rises to greater heights.
This zone is also known as the convective region since it is where all convection occurs and stops