UPSC Prelims 2000 Q42: Geography – Atmosphere & Climatology
- (a) I, II and III
- (b) II, III and IV
- (c) I, III and IV
- (d) I, II and IV
Answer: (b) II, III and IV
Explanation
The Roaring Forties
| Statement | Verdict |
|---|---|
| I. Blow uninterrupted in both hemispheres | Wrong — uninterrupted only in the Southern Hemisphere, which has little land at 40°-50° S |
| II. Blow with great strength and constancy | Correct |
| III. From the north-west in the Southern Hemisphere | Correct — westerlies, deflected left by the Coriolis force |
| IV. Overcast skies, rain and raw weather | Correct — a stormy belt of depressions |
The Roaring Forties are the strong westerlies of roughly 40°-50° South.
In the Southern Hemisphere there is almost no land at these latitudes, so the winds blow without interruption and with great strength and constancy; in the Northern Hemisphere the continents break them up.
Deflected by the Coriolis force, they blow from the north-west towards the east in the Southern Hemisphere.
They bring overcast skies, rain and raw, stormy weather; sailors called the next belts the Furious Fifties and Shrieking Sixties.
So statements II, III and IV are correct.
Answer: (b) II, III and IV.
Why each option is right or wrong
- (a) Incorrect. Statement I is wrong; they are uninterrupted only in the Southern Hemisphere.
- (b) CORRECT. Strong and constant, north-westerly in the south, and stormy.
- (c) Incorrect. It includes the wrong statement I and leaves out II.
- (d) Incorrect. Statement I is wrong, and statement III is correct.
Key point
Roaring Forties, Furious Fifties, Shrieking Sixties — all Southern Hemisphere westerlies.
Remember
Roaring Forties: 40°-50° S westerlies, strong, constant, stormy.
Common mistakes
- Thinking the westerlies are just as strong in the Northern Hemisphere.
- Forgetting the Coriolis deflection that makes them north-westerly in the south.
- Confusing them with the trade winds (easterlies of the tropics).
Exam tip
'Uninterrupted' needs open ocean → only the south.
Sources
- G.C. Leong — Certificate Physical and Human Geography (Oxford University Press)
- Savindra Singh — Climatology (Pravalika Publications), chapter on planetary winds