Normally the temperature decreases with the increase in height from the earth's surface, because:
- 1.the atmosphere can be heated upwards only from the Earth's surface
- 2.there is more moisture in the upper atmosphere
- 3.the air is less dense in the upper atmosphere
Select the correct answer using the codes given below:
- A.1 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2, 3
▶ Answer & Explanation
Correct answer: C. 1 and 3 only
The primary source of heat for the Earth's atmosphere is solar radiation, which warms the Earth's surface. This surface then heats the lower layers of the atmosphere through conduction, convection, and radiation. As altitude increases, the distance from this primary heat source (the Earth's surface) increases, leading to a decrease in temperature. While moisture content and air density do vary with altitude, they are not the fundamental reasons for the general decrease in temperature; rather, density decreases, and moisture generally decreases with height.
Source: UPSC gs1 2012