Question map
Which of the following statements about Tornadoes are correct? Tornadoes usually spin 1. anticlockwise in the northern hemisphere 2. clockwise in the southern hemisphere 3. clockwise in the northern hemisphere 4. anticlockwise in the southern hemisphere Select the correct answer using the code given below :
Explanation
Tornadoes are intense cyclonic rotations associated with extremely low-pressure systems [5]. In the Northern Hemisphere, the Coriolis force deflects winds to the right, initiating a counter-clockwise (anticlockwise) rotation around low-pressure centers [4]. Conversely, in the Southern Hemisphere, the Coriolis force deflects winds to the left, resulting in a clockwise rotation [3]. While tornadoes are often too small to be directly governed by the Coriolis effect—deriving their spin instead from vertical wind shear and mesocyclone formation—approximately 98% of them follow these hemispheric cyclonic patterns [2]. Therefore, tornadoes usually spin anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. Rare exceptions called anticyclonic tornadoes can spin in the opposite direction, but they represent a very small percentage of occurrences.
Sources
- [5] https://www.scientificamerican.com/article/fact-or-fiction-south-of-equator-tornadoes-spin-in-opposite-direction/
- [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 23: Pressure Systems and Wind System > Why Tropical Cyclones Do Not Form At The Equator? > p. 310
- [4] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 4: Climate of India > Tornado > p. 30
- [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 23: Pressure Systems and Wind System > UPSC Prelims 2011] Which one of the following weather conditions is indicated by a sudden fall in barometer reading? > p. 308
- [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 23: Pressure Systems and Wind System > Centripetal Acceleration > p. 309