UPSC CSE Prelims
Question 22
The jet aircrafts fly very easily and smoothly in the lower stratosphere. What could be the appropriate explanation ?
- There are no clouds or water vapour in the lower stratosphere.
- There are no vertical winds in the lower stratosphere.
Which of the statements given above is/are correct in this context ?
View correct answer and explanation
Correct answer: C
Correct Option: C
Explanation: The lower stratosphere generally has much less water vapour and deep convection than the troposphere, so aircraft often encounter fewer clouds and less turbulence.
Statement / Item-wise Analysis:
1: Correct - Correct as an approximation: the stratosphere is very dry and lacks ordinary weather clouds.
2: Correct - Correct in the intended context: stable stratification suppresses strong vertical air movements.
Option-wise Analysis:
A: Incorrect - omits supported item 2.
B: Incorrect - omits supported item 1.
C: Correct - includes the supported statements and excludes the unsupported ones.
D: Incorrect - omits supported items 1, 2.
Review Note: The categorical phrases “no clouds/water vapour” and “no vertical winds” are oversimplifications; rare stratospheric clouds and vertical motions exist.