Prelims 2011 · archive
EasyWesterlies in the southern hemisphere are stronger and persistent than in the northern hemisphere. Why?
- 1.Southern hemisphere has less landmass as compared to the northern hemisphere.
- 2.Coriolis force is higher in southern hemisphere as compared to northern hemisphere
Which of the statements given above is/are correct?
Answer & explanation
Answer: (a) 1 only
Westerlies blow more strongly and steadily in the southern mid-latitudes because the Southern Hemisphere has far less land to obstruct them than the Northern Hemisphere. The Coriolis force depends on latitude and not on which hemisphere, so it is not the cause.
- ✓ 1. The Southern Hemisphere mid-latitudes are mostly open ocean, with little land to break the wind; only parts of South America, Australia and New Zealand lie in the westerly belt. In the north, the large land masses of North America, Europe and Asia obstruct the airstream and weaken it.
- ✗ 2. The Coriolis force is absent at the equator and increases with latitude, reaching its maximum at the poles. It has the same strength at equal latitudes north or south. It only deflects winds in opposite directions: to the right in the north and to the left in the south. It is not 'higher' in the south.
Remember · Roaring Forties: Southern Hemisphere westerlies are strongest because there is little land to obstruct them. Coriolis force depends on latitude, not hemisphere.
📘 Read it in NCERT: Class 11 Fundamentals of Physical Geography, Ch 9 (practise this chapter)
Sources
- NOAA National Ocean Service – What are the Roaring Forties? ↗ “the large land masses of North America, Europe, and Asia obstruct the airstream, whereas, in the southern hemisphere, there is less land to break the wind in South America, Australia, and New Zealand.”
- NCERT Class 11 · Fundamentals of Physical Geography, Chapter 9 “The Coriolis force is directly proportional to the angle of latitude. It is maximum at the poles and is absent at the equator.”
Question: UPSC Civil Services (Preliminary) 2011, General Studies paper. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). ·