What is El Niño: Definition, How it Works, Global Conditions and Impact on India

El Niño is a major climate event that affects weather worldwide. It shows up every few years and can cause droughts in some places and heavy rains in others. Knowing about El Niño matters a lot, especially for farmers and people in countries like India, where the weather directly affects daily life.

Table of Contents

• Definition
• How does El Niño Work
• Global Conditions During El Niño
• Impact of El Niño on India

Definition

El Niño occurs when the surface waters in the central and eastern tropical Pacific Ocean become unusually warm. The name comes from Spanish and means “The Little Boy” or “Christ Child.” Peruvian fishermen came up with this name back in the 17th century because they noticed warmer ocean water near Christmas, which would affect their fish catch.

In scientific terms, El Niño is the warm phase of something called the ENSO cycle, which stands for El Niño-Southern Oscillation. This is a pattern of ocean and atmospheric changes in the tropical Pacific. The opposite of El Niño is La Niña, which is the cool phase. These two phases keep switching every two to seven years and affect weather patterns all over the world.

How does El Niño Work

Under normal conditions, strong winds blow from east to west across the tropical Pacific. These winds push warm water toward Australia and Southeast Asia. At the same time, cold water from deep in the ocean rises near the coast of South America. This keeps the western Pacific warm and the eastern Pacific cooler.

During El Niño, these winds slow down or sometimes reverse. Without the winds pushing warm water west, it stays in the central and eastern Pacific. The water temperature there can go up by 1 to 3°C and sometimes even more during strong events.

This change in ocean heat affects wind and rain patterns around the world. Monsoons get disrupted, rain shifts to unexpected places and normal weather patterns are thrown off. An El Niño usually starts between April and June, gets strongest around December and fades away the following spring.

Global Conditions During El Niño

El Niño affects every part of the world in different ways:

Americas: Peru and Ecuador get a lot of rain and face flooding, which damages farms and infrastructure. Southern Brazil and Argentina often go through drought. The southern United States usually gets more rain than normal, while the Pacific Northwest tends to have warmer and drier winters.

Asia and Australia: Australia is hit hard, often dealing with drought, more bushfires and lower farm output. Indonesia and the Philippines also see drier conditions, which can lead to forest fires and water shortages.

Africa: East Africa tends to get more rain during El Niño, which can cause floods and spread waterborne diseases. Southern Africa, on the other hand, often faces drought, which puts food security at risk.

Europe: El Niño's effect on Europe is not as direct, but research shows it can affect winter temperatures and storm patterns, bringing warmer and wetter winters to some areas.

Strong El Niño events, like those in 1997-98 and 2015-16, caused massive economic damage, food shortages and even disease outbreaks.

Impact of El Niño on India

India is especially affected by El Niño because of how it messes with the Southwest Monsoon, which brings about 70% of India's yearly rainfall between June and September.

Monsoon Disruption: El Niño weakens the Indian monsoon by disturbing a large-scale wind system called the Walker Circulation. During El Niño years, India usually gets less rain than normal. Looking at history, big droughts in India, like those in 1987, 2002 and 2009, all happened during El Niño years.

Agricultural Impact: More than half of India's workforce depends on farming and farming depends on the monsoon. Less rain means lower output of kharif crops like rice, pulses and oilseeds. This pushes up food prices and causes hardship in rural areas.

Water Resources: When rainfall drops, reservoirs, groundwater and rivers all suffer. This affects both drinking water and irrigation. States like Maharashtra, Karnataka, Rajasthan and Odisha have historically struggled the most during these times.

Economic Consequences: Lower farm output, higher food prices and more spending on drought relief can slow down India's economy. In years when El Niño causes serious monsoon failures, GDP growth has taken a hit.

Mitigating Factors: Not every El Niño year leads to drought in India. A climate pattern called the Indian Ocean Dipole (IOD), when it's positive, can reduce El Niño's drying effect. Better weather forecasting also helps now. The India Meteorological Department (IMD) can give early warnings so people and governments can prepare ahead of time.