April 8, 2019

Layers of Atmosphere of the Earth

Contents

The atmosphere is composed of gases, water vapor and dust particles.
Mixer of dust particle and water vapor are called aerosol.
It receives Incoming solar energy from the sun giving rise to climate.
We actually live at the bottom of this indefinite layer of atmosphere
One estimate puts this limit at about 600 miles (950 km) above sea level.
99% of the total mass of the atmosphere is confined to the height of 32 km from the earth’s surface.

Composition of Atmosphere of the Earth

The proportion of Gases changes in the higher layers of the atmosphere.
Oxygen will be almost in negligible quantity at the height of 120 km.
Similarly, carbon dioxide and water vapor are found only up to 90 km from the surface of the earth.

It is constituting 2% to 4% of the total volume.
90% of moisture content in the atmosphere exists within 6 km of the surface of the earth.
Water vapor plays a significant role in the insulating action, of the atmosphere.
It absorbs long-wave terrestrial radiation and part of the incoming solar radiation.
Water vapor is the source of precipitation and clouds.

It consists of sand particles, pollen grains, small organisms, soot, ocean salts
These solid particles perform the function of absorbing, reflecting and scattering the radiation.
It is responsible for the orange and red colors at sunset and sunrise
Blue color of the sky is due to selective scattering by dust particles.
Dust particles are an important factor in the formation of clouds, fog and hailstones.

Layers of Atmosphere of the Earth

The atmosphere consists of different layers with varying density and temperature.
Density is the highest near the surface of the earth and decreases with increasing altitude.
The column of atmosphere is divided into 5 different layers depending upon the temperature condition.

The troposphere is the lowermost layer of the atmosphere.
Its average height is 13 km.
It extends roughly to a height of 8 km near the poles and about 18 km at the equator.
The thickness is greater at the equator because heat is transported to great heights by strong convectional currents.
The temperature in this layer, as one goes upwards, falls at the rate of 5°C / km
It reaches -45 °C at the poles and -80 °C at the equator.
The fall in temperature is called ‘lapse rate’.
The troposphere is marked by temperature inversion, turbulence and eddies.
Almost all whether activities like rainfall, fog and hailstorm etc. happens in this layer.

Layers of Atmosphere of the Earth

Stratosphere extends up to an altitude of 50 km from the earth’s surface.
The temperature rises to reach a level of 0°C at 50 km altitude.
This rise is due to the presence of ozonosphere.
Stratosphere layer is ideal for flying airplanes.
Sometimes, cirrus clouds are present at lower levels in this layer.

Ozonosphere lies at an altitude between 30 km and 60 km from the earth’s surface.
It is a part of Stratosphere.
This layer absorbs ultraviolet radiation.
The ozonosphere is also called chemosphere

In thermosphere temperature rises very rapidly with increasing height.
Ionosphere is a part of this layer.
It’s an electrically charged layer
It extends between 80-400 km.
Ionosphere helps in radio transmission.
Thermosphere is also known as exosphere
Person would not feel warm because of the thermosphere’s extremely low pressure.
The International Space Station and satellites orbit in this layer.
Auroras are observed in lower parts of this layer.
Light gases like helium and hydrogen float into the space from here.