Question map
Westerlies in southern hemisphere are stronger and persistent than in northern hemisphere. Why? 1. Southern hemisphere has less landmass as compared to northern hemisphere. 2. Coriolis force is higher in southern hemisphere as compared to northern hemisphere. Which of the statements given above is/ are correct?
Explanation
The Westerlies in the Southern Hemisphere are significantly stronger and more persistent than those in the Northern Hemisphere primarily due to the vast expanse of open ocean and the relative lack of landmass [5]. In the Northern Hemisphere, large landmasses create friction and disrupt the flow of air, whereas the Southern Hemisphere's extensive water surfaces offer minimal resistance, allowing winds to reach high velocities, famously known as the 'Roaring Forties' [3]. Statement 2 is incorrect because the Coriolis force is a function of the Earth's rotation and latitude; it is not inherently stronger in one hemisphere than the other at the same latitude [4]. The Coriolis force is zero at the equator and reaches its maximum at the poles in both hemispheres [6]. Therefore, the difference in wind strength is attributed to land-sea distribution and temperature gradients rather than variations in the Coriolis force [3].
Sources
- [3] https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2000-6A%20Chap%204-6.pdf
- [5] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 14: Climate > Pressure and Planetary Winds > p. 140
- [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 26: Tropical Cyclones > High Wind Shear In The Southern Hemisphere > p. 369
- [4] https://education.nationalgeographic.org/resource/coriolis-effect/
- [6] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 14: Climate > Pressure and Planetary Winds > p. 139