Climate Change

IMD confirms weak El Nino conditions

In India, there is a relationship between El Nino events and hotter than usual summers along with a decrease in rainfall during the monsoon

 
By Akshit Sangomla
Last Updated: Friday 29 March 2019
Photo: Agnimirh Basu

The India Meteorological Department (IMD) has finally declared that weak El Nino conditions are prevalent in the equatorial Pacific Ocean. In a March 29 press release, the IMD said “these conditions are likely to persist in early part of the summer season and likely to weaken thereafter.”

El Nino, which is the unusual warming of the equatorial Pacific Ocean, disrupts global wind patterns affecting climatic conditions in tropical areas like Africa, sub-tropical areas like India as well as the extra-tropical areas like North America. 

In India, there is a relationship between El Nino events and hotter than usual summers along with a decrease in rainfall during the monsoon. Most of the time, these events have also led to drought conditions.

The weak El Nino might have an effect on the onset and intensity of monsoon this year, an update on which is expected soon from the government of India.

In the 135 years between 1880 and 2014, around 90 per cent of all evolving El Nino years have seen below normal rainfall, and 65 per cent of them experienced droughts, according to Skymet weather. In fact, six of the worst droughts in the country since 1871 have been triggered by El Nino — the most recent being in 2009.

The last El Nino event that ended in 2016 had lasted for two years and caused heat waves all around the world, including India. The heat waves in 2015 and 2016 killed more than 2,500 people in India, and have been attributed to climate change — suggesting that El Nino was intensified by global warming.

The severe El Nino had also caused massive coral bleaching in the Great Barrier Reef and droughts in parts of Africa, South East Asia and South America. Last year, too, Australia underwent its worst drought in living memory — in regions like the New South Wales the drought was the worst in 400 years.

But the acknowledgement of the current El Nino comes after some delay. Even till last week, the IMD had maintained that “warm ENSO neutral conditions are prevailing over equatorial Pacific Ocean” and that they are likely to remain near to the El Nino threshold value during the next two months.

In the latest press release, the IMD said that the weak El Nino will persist for the early part of the summer season.

On the other hand, weather agencies in other countries had declared weak El Nino conditions at the beginning of 2019. In January, Japan’s Meteorological Agency (JMA), which is also the Asian arm of the World Meteorological Organisation (WMO), said El Nino conditions were prevailing and that there was 80 per cent chance of an El Nino phenomenon staying till spring season of 2019.

The Climate Prediction Centre (CPC) of the National Weather Service in the United States of America also concluded, around the same time, that weak El Nino conditions had formed in the equatorial Pacific Ocean. In a March 14, 2019 update, the CPC says that “weak El Niño conditions are likely to continue through the Northern Hemisphere spring 2019 with an 80 per cent probability and summer with a 60 per cent probability”.

The preliminary impact of a weak El Nino can already be seen with the rising temperatures and heat waves across the country. In early March, the heat wave season began in many areas of Tamil Nadu, coastal Andhra Pradesh and Rayalaseema.

On March 6, Tamil Nadu’s Dharmapuri station recorded a maximum temperature of 40.2 degree Celsius which is the highest temperature ever recorded at the place in March. The previous record was 40 degree Celsius — recorded in 1996.

In Andhra Pradesh, while two meteorological stations at Tirupathi and Cuddapah in the Rayalaseema region recorded maximum temperatures of 40.4 degree Celsius and 40 degree Celsius, five other stations recorded temperatures above 38 degree Celsius.

But then in late March an unusual heat wave affected Kerala, taking weather forecasters by surprise. It has killed four people till date and almost 300 people have suffered from sun burns, according to media reports.

One third of these cases were reported on March 27. The local IMD in fact blamed the heat wave on El Nino. “Temperature rise of one degree celsius above normal are usual in pre-monsoon summer. But this time, it is up by 3 to 4 degrees Celsius, which is abnormal. We see the development of El Nino behind this,” Santhosh K, IMD Kerala director had told Down to Earth.

Now the heat waves have spread to Gujarat, Maharashtra and Odisha as well. Heat waves are the third highest cause for deaths among natural disasters in India, after lightning strikes and earthquakes; but the Indian government does not consider it as a natural calamity.

In fact, the IMD came up with advisories for heat waves only in 2016 — the first time in the institution’s 140 year-history. The heat waves of 2015 and 2016 had killed 2,040 and 1,111 people across the country respectively.

In nine out of the last 10 years (till 2017) India has suffered from heat waves which have killed close to 8,000 people. Andhra Pradesh and Telangana seem to be particularly vulnerable to deaths due to heat wave conditions.

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