How Could El Nino Affect India's Monsoons Later This Year? Experts Explain

In April 2023, Indian Meteorological Department (IMD) in its monsoon forecast had said that El Nino conditions were likely to occur during the season. The World Meteorological Organization (WMO) too in an update on May 3 emphasised that "the likelihood of El Niño developing later this year is increasing."

India being an agrarian economy relies heavily on the timely arrival of monsoons for stable agricultural production. El Nino conditions during monsoons could significantly impact crops. Since the onset of the monsoon is a crucial time for agriculture in India, The Core spoke to climate experts to understand El Nino's impact on the monsoon rainfall and on the agricultural sector.

What is El Nino?

El Nino is a naturally occurring climate pattern associated with the warming of the ocean surface temperatures in the central and eastern tropical Pacific Ocean. Explaining the phenomenon Roxy Mathew Koll, Climate Scientist at the Indian Institute of Tropical Meteorology, said that the Pacific goes through episodes of warm (El Nino) and cool (La Nina) waters during a five to seven-year period. This is known as the El Niño Southern Oscillation (ENSO). El Nino generally weakens the trade winds, dampens the monsoon circulation, and causes reduced rainfall in the Indian subcontinent.

After persisting for three years, La Nina has dissipated, and at present, the tropical Pacific is experiencing an ENSO-neutral phase. This means there is neither El Nino nor La Nina. According to Koll, as oceans absorb more than 93% of the additional heat from global warming, El Ninos are also getting stronger. Though El Ninos peaks during December, observations show that the warm waters are developing. Forecasts indicate that by June-July the El Nino could mature and be strong enough to affect the Indian monsoon.

As far as the frequency is concerned, the whole cycle of the El Nino southern oscillation is not a consistent pattern. "In the past, in 2014 and 2015, we had El Nino and then '16, we had La Nina '17 was neutral, '18 and '19 again there was El Nino, so the whole cycle varies between two to seven years, but it's not a precise cycle that you would have El Nino this year or La Nina next year," Akshay Deoras, a research scientist at the National Centre for Atmospheric Science and the Department of Meteorology, University of Reading, UK, said.

How will El Nino impact India?

Quantitatively, the southwest seasonal monsoon from the month of June to September is predicted to be 96%. However, based on the current conditions, IMD will issue updated forecasts in the last week of May.

AVM Sharma, President (Meteorology & Climate Change) of Skymet Weather reiterated that this will be an El Nino year, and the seasonal rainfall for the Indian region will be affected in multiple locations. El Nino is often associated with increased heat, drought, or rainfall in different parts of the world.

Elaborating on how the El Nino progresses, Deoras said, "The onset of the southwest monsoon over Kerala gets delayed by a couple of days. However, that's something that could change every year depending on what weather conditions form. In the past years, we have seen that the June-September average rainfall across India gets into this below-average category. Across India, we get reduced southwest monsoon rainfall and enhanced northeast monsoon rainfalls."

What implications will it have on the agricultural sector in India?

No two El Nino events are the same and the effects depend partly on the time of year. In terms of agriculture, what happens in June and the first fortnight of July is crucial for the sowing season. Deoras said that in 2015, June received good rainfall across the country and from July onwards, the impact of a strong El Nino started coming into existence, which resulted in good sowing, followed by a dry spell in July, August, and September. He said, "This year, if it doesn't rain properly from June itself, then in that case, Kharif sowing across the entire country will be affected, particularly areas where there is not enough irrigation coverage." The rainy season in India is generally from June to September, in which kharif crops like paddy, maize, soybean, groundnut, and cotton are grown, which require large volumes of water.

If June ends on a good note, then sowing would be fine. However, the survival of seeds and other factors like distribution will depend on the weather as crops need consistent rain during the four-month season. "It's quite hard to say what will happen but the understanding is that the rainfall across India, would be less than the average and in particular, certain states like Maharashtra, Gujarat, Madhya Pradesh and then further into the east they would be more affected," he added.

Sharma said explained that El Nino affects largely the central and northern parts of the country. The southern and northeastern parts are mildly affected, which is why northeastern parts have sufficient rainfall, rather than excess rainfall during monsoon. This means that even if there is a deficiency of 5-15% it may not have a major impact in the eastern parts of the country.

However, the deficiency in rainfall matters for the central and north-western parts of the country which are the 'agri bowl' for Kharif crops. "Fifty percent of your agricultural land in these areas is dependent on monsoon rainfall. Forty percent of our food grain comes from these pockets, which are monsoon dependent. All the crops in these particular regions, namely the states, Kashmir, Punjab, Haryana, Delhi, Uttar Pradesh, Gujarat, Rajasthan, Maharashtra, Chhattisgarh, West Bengal, Orissa, Bihar, Jharkhand will be at risk of deficit rainfall" he said.