Why In News?

A developing "Super El Niño" in 2026, with temperatures projected to exceed 2°C above average, poses a high risk of below-normal monsoon rainfall for India.

What is Super El Nino?

While El Niño is the "warm phase" of the El Niño-Southern Oscillation (ENSO), a Super El Niño is defined by its intensity. 

• Standard El Niño: Declared when sea surface temperature (SST) in the central/eastern Pacific (Niño 3.4 region) rises 0.5°C above the long-term average.
• Super El Niño: An unofficial but widely used term for events where SST anomalies surpass 2.0°C (some definitions use 2.5°C).
• The Distinction: It is not just "warmer water"; it represents a massive injection of oceanic heat into the atmosphere, capable of altering the global Jet Stream and weather patterns far more aggressively than a standard event. 

Rarity: Standard El Niño events occur every 2–7 years, but "Super" events are rare, with only three recorded in the last 40 years: 1982-83, 1997-98, and 2015-16. 

The Mechanism of "Super" El Niño

Phase 1: The Collapse of Trade Winds

• Normal State: Trade winds blow East -> West, piling warm water near Indonesia.
• Super El Niño Shift: The trade winds don't just weaken; they often reverse (West -> East). This is often triggered by "Westerly Wind Bursts" (WWBs). 

Phase 2: The Kelvin Wave Surge

• This reversal triggers massive internal ocean waves called Kelvin Waves.
• These waves carry the colossal pool of warm water from the Western Pacific (near Asia) to the Eastern Pacific (near Peru) over a span of 2-3 months.  

Phase 3: Thermocline Deepening

• The Thermocline (the barrier between warm surface water and cold deep water) is pushed deep underwater in the Eastern Pacific.
• Result: The nutrient-rich cold water cannot rise to the surface (upwelling stops), leading to the collapse of fisheries (anchovies) and releasing immense heat into the atmosphere.  

Impacts of Super El Nino

• Impact on India:
• Monsoon Suppression: It causes a severe deficit in the Southwest Monsoon, as the rising limb of the Walker Circulation shifts away from the Indian landmass.
• Agricultural Distress: High risk to Kharif crops (Rice, Tur, Soyabean), leading to food inflation.
• Extreme Heat: Linked to more frequent and intense heatwaves during the pre-monsoon months.
• Global Consequences:
• South America: Devastating floods in Peru and Ecuador.
• Australia & Indonesia: Catastrophic droughts and uncontrollable bushfires.
• Marine Ecosystems: Mass Coral Bleaching due to prolonged thermal stress.

Climate Change Impact

Recent studies suggest that while the frequency of El Niño might not change, the intensity of "Extreme" or "Super" events is likely to increase due to global warming. The warming of the Pacific is becoming more non-uniform, making climate prediction models more complex.

 Source: DOWNTOEARTH