La Nina

 

Context:

  • Various parts of India, especially North India, have been experiencing a severe cold wave. Warnings for the severe cold waves have been issued in several northern states.

 

What brings cold to the region?

  • It is the unabated north-westerly winds which bring chilly winds from higher latitude to Indo-Gangetic plains. 
  • However, passage of back-to-back western disturbances tend to change the wind direction from cold north-westerlies to warm and humid easterlies.
  • However, with La Niña in place, what is expected is less amount of winter rains and thus, icy cold winds would continue to blow over Northwest India uninterruptedly, bringing down the temperatures.”

 

 

What are El Niño and La Niña?

  • They are two natural climate phenomena occurring across the tropical Pacific Ocean and influence the weather conditions all over the world.
  • While the El Niño period is characterized by warming or increased sea surface temperatures in the central and eastern tropical Pacific Ocean, a La Niña event causes the water in the eastern Pacific Ocean to be colder than usual.
  • Together, they are called ENSO or El Niño-Southern Oscillation.

 

 

Weather changes because of La Nina:
  • The Horn of Africa and central Asia will see below average rainfall due to La Niña.
  • East Africa is forecast to see drier-than-usual conditions, which together with the existing impacts of the desert locust invasion, may add to regional food insecurity.
  • It could also lead to increased rainfall in southern Africa.
  • It could also affect the South West Indian Ocean Tropical Cyclone season, reducing the intensity.

Source: THE HINDU.

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