The El Nino factor – Forecasting the monsoon | 4th March 2023 | UPSC Daily Editorial Analysis

What's the article about?

• It talks about the impact of various factors such as La Nina, El Nino and IOD on the Indian Monsoon.

Relevance:

• GS1: Important Geophysical Phenomena;
• GS3: Indian Agriculture;
• Prelims

Context:

• The Union finance ministry issued a statement that the predictions of a return of El Nino could presage a weaker monsoon, resulting in lower agricultural output and higher prices.
• The writer attempts to draw a link between La Nina, the strength of the Indian Monsoon, and agricultural output in this article.

Analysis:

• Impact of La Nina and El Nino on the Indian Monsoon:
  • During the last four years, the southwest monsoon has been bountiful with normal and above normal rainfall from June to September.
  • Although this highly complex, dynamic system arrives with unfailing regularity, there are many factors responsible for its behaviour.
  • One is the El Nino factor associated with the warming of sea-surface waters in the central and eastern tropical Pacific Ocean, which tends to weaken the southwest monsoon over India.
  • The cooling of such waters is referred to as the La Nina factor, which results in a marked increase in rainfall.
  • One reason India had a good run of southwest monsoons is the “triple dip” La Nina which extended over three consecutive winters.
    • ‘Triple Dip’ La Niña is a period where the La Niña period extends for up to three consecutive winters and results in multiyear cooling of the surface temperature of the equatorial Pacific Ocean.
  • The cause for concern now is that the US weather agency, National Oceanic and Atmospheric Administration, has forecast that El Nino could return as early as June when the southwest monsoon hits the coast of Kerala.
• Link between monsoon rainfall and agricultural output:
  • There is definitely a link between monsoon rainfall and agricultural output.
  • During the last nine years, there were five years of normal and above normal rains (2016, 2019, 2020, 2021 and 2022) when India’s agricultural sector grew at an average annual rate of 4.6%.
  • But when the rains were deficient or below normal (2014, 2015, 2017 and 2018) annual agricultural growth averaged only 2.4%.
• Other factors that have influence on the Indian Monsoon: Indian Ocean Dipole and Eurasian snow cover.
  • While positive Indian Ocean Dipole conditions are good for rainfall, negative conditions have the effect of suppressing monsoon bursts over the Indian subcontinent.
  • Eurasian snow cover, the ninth-lowest reported in the last 67 years, has an inverse relationship with the monsoon.

Way Forward:

• While El Nino undeniably had an impact on deficient rainfall during 2014 and 2015, its impact is less clear on other episodes of below normal rainfall in the country.
• Greater clarity on El Nino will, of course, become available when the IMD makes its first long-term forecast for the monsoon by April.
• As the rains have a crucial bearing on India’s agricultural output, the IMD must beef up its capabilities in location-specific forecasting so that suitable adaptive measures can be taken by farmers during the forthcoming kharif season.