El Niño and the ENSO Mechanism
El Niño is the warm phase of the El Niño–Southern Oscillation (ENSO) — a coupled ocean-atmosphere phenomenon centred on the tropical Pacific Ocean. Under normal (neutral) conditions, strong trade winds blow westward along the equator, pushing warm surface water toward Asia and Australia, while cold, nutrient-rich water upwells near the South American coast. During El Niño, trade winds weaken or reverse. Warm water shifts eastward toward the Americas, disrupting the Walker Circulation (the equatorial atmospheric convection loop). This reorganisation alters pressure systems and precipitation patterns globally. For South Asia, El Niño typically correlates with a weakened or erratic Indian Summer Monsoon — reducing Kharif crop output and raising food prices. India experienced significant El Niño-linked monsoon deficits in 1987, 2002, 2009, and 2023.
- ENSO phases: El Niño (warm/positive), La Niña (cold/negative), Neutral
- Walker Circulation: the east-west atmospheric convection loop over the equatorial Pacific — disrupted during El Niño
- El Niño's impact on India: weakens the southwest monsoon, raising risk of drought and below-normal Kharif output
- A "Super El Niño" (like 1997–98) can cause more severe and prolonged disruptions; one is forecast for potential development in late 2026
- Indian Ocean Dipole (IOD) can partially offset El Niño effects on India — a positive IOD tends to bring more moisture to India
● Tracked since May 08, 2026 · last seen July 03, 2026 · updates as the daily brief publishes