Tornadoes

Tornadoes

In recent years, many tornadoes have formed across India due to warming Bay of Bengal

  • Tornadoes – Land-based vertical column of violently rotating air that extends from thunderstorm to ground.
  • Origin –
    • Tornado formation typically needs 4 ingredients: Shear, Lift, Instability, and Moisture.
    • When there is wind shear, sometimes the winds begin to roll into a horizontal column of air.
    • Once there is a strong updraft of air being transported from the ground to the atmosphere, that column of air becomes vertical. That is when a storm usually develops in this scenario.
    • As the storm develops, it turns into a supercell thunderstorm. Supercells are storms that rotate and spin.
    • With both the vertical, rotating column of air and the supercell thunderstorm together, that may bring down a tornado from the storm cloud.
Image Credits: Britannica
  • Seasonal variations – Most common in spring and least common in winter. 
  • Mostly occurred in – United States, Argentina and Bangladesh.
  • Tornadoes in India – Reported in Eastern states of West Bengal, Odisha, and Jharkhand during pre-monsoon period.
    • However, Tornadoes, unlike cyclones, have a relatively low frequency of occurrence in India.
                Parameters                 Tropical Cyclones           Tornadoes
  Size and Scale    Can span hundreds of miles and affect vast areas    Size is only a few hundred yards in diameter.  
  Wind Shear    Require very low values of tropospheric vertical shear.    Require substantial vertical shear of horizontal winds.  
  Temperature Gradient    Generated in regions of near-zero horizontal temperature gradient.    Produced in regions of large temperature gradient.  
  Area of Formation    Purely an oceanic phenomenon  Primarily developed over land.
  Time-Scale      Lifetime that is measured in days      Typically lasts on the scale of minutes  
  Impact    Heavy rainfall, storm surges, and widespread flooding    Cause Localized destruction.  

Source: The Indian Express


Previous Year Question

Consider the following statements:
1. Jet streams occur in the Northern Hemisphere only.
2. Only some cyclones develop an eye.
3. The temperature inside the eye of a cyclone is nearly 10°C less than that of the surroundings.
Which of the statements given above is/are correct?

[UPSC Civil Service Exam – 2020 Prelims]

(a) 1 only
(b) 2 and 3 only
(c) 2 only
(d) 1 and 3 only

Answer: (c)
Explanation:
Statement 1 is incorrect.
Jet streams occur both in the Northern Hemisphere as well as in the Southern Hemisphere.
Statement 3 is incorrect.
The eye is the region of lowest surface pressure and warmest temperatures.


Practice Question

Consider the following statements regarding Tornadoes:

  1. On a global scale, tornadoes mostly occur near to the regions of United States and Argentina.
  2. Tropical cyclones are purely an oceanic phenomenon whereas tornadoes are primarily developed over land.

Which of the statements is/are correct?

 
 
 
 

Question 1 of 1

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