El Niño Southern Oscillation (ENSO)

The year 2026 is being called an El Niño year due to extreme summers and heatwave conditions. ENSO is currently relevant for understanding heatwaves, monsoon variability, and global weather disruptions.

El Niño Southern Oscillation (ENSO):

Dimension	Key Details
ENSO	El Niño Southern Oscillation is a climate phenomenon involving changes in sea-surface temperatures in the eastern Pacific Ocean and atmospheric circulation.
Global Impact	ENSO can alter global atmospheric circulation and influence weather patterns across the world.
Phases	ENSO has three phases: 1. El Niño, 2. La Niña, and 3. Neutral.
Cycle	ENSO occurs in irregular cycles of 2 to 7 years.
El Niño	El Niño is the warm phase of ENSO, during which eastern Pacific surface waters become unusually warm.
El Niño Impact on India	El Niño can weaken or delay the Indian monsoon and cause dry spells in major agricultural states.
Heatwave Link	The frequency and severity of heatwaves in India are linked with El Niño conditions.
La Niña	La Niña is the cool phase of ENSO, marked by cooling of surface waters in the eastern Pacific Ocean.
La Niña Impact on India	La Niña usually strengthens moisture-bearing winds and boosts the southwest monsoon over India.
La Niña Risk	Strong La Niña conditions may cause excessive rainfall, flooding, and crop damage.
Neutral Phase	In the neutral phase, normal east-to-west winds push warm waters towards Indonesia, while cooler waters rise near South America.
Madden-Julian Oscillation	MJO is a moving system of wind, cloud, and pressure that brings rainfall as it travels around the equator.
MJO Movement	MJO moves eastward at around 4–8 metres per second and can circle the globe in 30 to 60 days.
MJO Impact on India	In a favourable phase, MJO can enhance rainfall over India during the monsoon season.