The secondary monsoon: On rainfall behaviour (The Hindu)

Mains Paper 1: Geography
Prelims level: El Niño
Mains level: Geographical phenomena and climate change

Context

•  There have been problems in prediction of onset of monsoon in India.
•  There is little understanding of the behaviour of the Indian Ocean and monsoon impact.

More about Indian Monsoon:

•  India's climate is affected by two seasonal winds - the northeast monsoon and the southwest monsoon.
•  South-west monsoon, known as summer monsoon blows from sea to land after crossing the Indian Ocean, the Arabian Sea, and the Bay of Bengal. The southwest monsoon brings most of the rainfall during a year in the country.
•  Whereas the north-east monsoon, commonly known as winter monsoon or retreating Monsoon blows from land to sea.

Why this year is so unique?

•  This year it had been the most delayed withdrawal of the monsoon since 1961but both the quantity and the timing had no effect on the onset of the northeast monsoon, which officially commenced on17th Oct.
•  This summer, the IMD and other meteorological agencies around the world, bet that monsoon rains would be on the lower side due to the possible emergence of an El Niño.
•  But the threat of El Niño had waned and India experienced torrential rains in August and September. This wasn’t predicted by our authorities and department.
•  Conditions in the Indian Ocean turned favourable and led to the excessive monsoon activity this year. Monsoon rains in south India have been 15% above normal.
•  In Andhra Pradesh, Telangana, Karnataka, Kerala and Tamil Nadu, where the Central Water Commission monitors over 30 reservoirs, their water levels were 44.2 billion cubic meters, or 84% of their total live capacity, and much higher than the 10-year average of 66%.
•  This shows that there is a deficit in understanding the behaviour of the Indian Ocean and its influence on the monsoons.

What is an El Niño?

•  It is a climate phenomenon that occurs when a vast pool of water in the eastern tropical Pacific Ocean becomes abnormally warm. Under normal conditions, the warm water and the rains it drives are in the western Pacific. El Niño occurs every few years.

What is the problem?

•  The influence of factors and their correlation on SOUTH-WEST monsoon is well studied.
•  The influence of temperatures in the Central Pacific, or land surface air temperature in northwestern Europe, quantity and distribution of monsoon rainfall in the south west
  monsoon is well understood but not on North-east monsoon.
•  For NE monsoon, which contributes about 20% of India’s annual rainfall and span October-December, there are no definite parameters evolved for prediction. Predictions for NE monsoon are only in terms of a few months.
•  The El Niño phenomenon, which has been linked to the abnormal warming of the equatorial waters off the central and eastern Pacific, has been connected with the failure of the southwest monsoon.
•  However, researchers over the years have noted that this had an opposite effect on the NE monsoon leading to more voluminous showers in the winter and particularly over South India.
•  This shows that there is a lack in understanding the behaviour of the Indian Ocean and its influence on the monsoons.
•  Though today India is moving to a system where dynamical models that run on powerful computers but these too are heavily reliant on the behaviour of the Pacific Ocean and El Niño-related swings.
•  India needs to step up research to improve the performance of these models.

Way forward

•  Giving more importance to understanding the vagaries of the NE monsoon and Indian
• Ocean should be among India’s key prongs to adapting to climate change and better forecasting.

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Prelims Questions:

Q.1) With reference to the Superconductivity, consider the following statements:
1. It is a phenomenon of exactly zero electrical resistance and expulsion of magnetic flux fields occurring in certain materials, called superconductors, when cooled above a characteristic critical temperature.
2. Recently researchers at the University of Chicago in the US have discovered superconductivity at the highest temperatures ever recorded.

Which of the statements given above are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) None of the above

Ans: B
Mains Questions:
Q.1) Why this year monsoon is so unique? What are the problems?