Question

In Text Questions
14.1
. What are the major atmospheric layers ? 1.4.2. Name three gases present in troposphere?
1.1.3. Why the tropospheric atmosphere is turbulent? 1.1.4. How the density of air vary with
increase of altitude ? 1.1.5. In stratosphere why there is a trend of increasing temperature with
increasing altitude ? 14.6. Which is the coldest region of atmosphere?
Act 1 1 1​

Answer 1

Answer:

14.1 The atmosphere is comprised of layers based on temperature. These layers are the troposphere, stratosphere, mesosphere and thermosphere. A further region at about 500 km above the Earth's surface is called the exosphere.

14.2 Three gases present in troposphere are :-

(i) Nitrogen 78% (ii) Oxygen 21% (iii) Argon 9%

14.3 When the rate of temperature decrease with height exceeds the adiabatic lapse rate for a region of the atmosphere, turbulence is generated. This is due to the convective overturn of the air as the warmer lower-level air rises and mixes with the cooler air aloft.

14.4 The density of air decreases with height. There are two reasons: at higher altitudes, there is less air pushing down from above, and gravity is weaker farther from Earth's center. So at higher altitudes, air molecules can spread out more, and air density decreases.

14.5 Temperature in the stratosphere rises with increasing altitude, because the ozone layer absorbs the greater part of the solar ultraviolet radiation. The ozone layer is an absorbing agent that protects life on Earth.

14.6 Mesosphere is the coldest region of atmosphere.