Which one among the following statements is NOT correct regarding the La Niña event of the global climate system?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → It refers to abnormal warming of sea surface water in central and eastern tropical Pacific Ocean
The question asks for the statement that is not true of La Niña. La Niña is the cold phase of the Pacific climate cycle: strong trade winds push warm surface water west towards Asia and Australia, and cold water rises off the coast of South America. Its opposite, the warm phase, is El Niño.
Option (1) It causes drought in Peru and Ecuador and heavy floods in Australia — True of La Niña (Incorrect). The cold water off South America keeps the coast of Peru and Ecuador dry, while the warm water piled up in the west brings heavy rain and floods to Australia.
Option (2) It is beneficial for the Indian monsoon and aids rainfall across India — True of La Niña (Incorrect). La Niña years usually bring a normal or above-normal monsoon to India.
Option (3) It refers to abnormal cooling of sea surface water in central and eastern tropical Pacific Ocean — True of La Niña (Incorrect). This is the definition of La Niña.
Option (4) It refers to abnormal warming of sea surface water in central and eastern tropical Pacific Ocean — Not true of La Niña (Correct). Abnormal warming of this water is El Niño, which usually weakens the Indian monsoon.