Question

The nearest atmospheric layer to the earth surface is:

• A. Stratosphere
• B. Mesosphere
• C. Troposphere
• D. Thermosphere

Answer 1

Answer:

C. Troposphere

Atmosphere

• The composition of the atmosphere is somewhat uniform up to about 90 Kilometers from the surface of the earth

• This part of the atmosphere is called homosphere.

• Beyond this there is no uniformity in the gaseous composition. So the part of the atmosphere beyond 90 km from the earth is called as heterosphere.

The atmosphere can be divided into four layers or zones on the basis of its altitude and thermal condition. Temperature variation are experienced as its altitude increases from the earth. Atmospheric layers:

• Troposphere

• Mesosphere

• Stratosphere

• Thermosphere

Troposphere

• The height of the troposphere is more in the equatorial regions because of strong convection here. (about 18km)

• Almost all the weather and climatic phenomena such as cloud formation, rain, snow, wind, thunder and lightning etc. Take place in this layer

• In the troposphere the temperature decreases at a uniform rate of 1° Celcius for every 165 metres of altitude. This is called Normal Lapse Rate.

• The zone of transition above the troposphere is called tropopause.