El Niño and La Niña

Why in News?

Recently, the World Meteorological Organization (WMO) has warned that an El Niño event is highly likely to develop, with an 80% chance during June–August.

El Nino (Warm Phase)

• El Niño – It is a natural climate pattern characterized by the warming of ocean surface temperatures in the central and eastern tropical Pacific Ocean.
• Trade winds weaken or reverse.
• Warm water shifts eastward toward South America.
• Effects on India – Often associated with weaker southwest monsoon rainfall.
• Can increase the likelihood of drought conditions and heat waves.
• Global Effects – Droughts in Australia and parts of Southeast Asia.
• Increased rainfall in western South America.
• Warmer global temperatures.
• 

La Niña (Cool Phase)

• La Niña – Sea surface temperatures in the central and eastern tropical Pacific become cooler than normal.
• Trade winds strengthen.
• Warm water is pushed further west toward Asia and Australia.
• Effects on India – Generally linked to stronger monsoon rainfall.
• Can increase the risk of floods in some regions.
• Global Effects – Wetter conditions in Australia and Southeast Asia.
• Drier conditions in western South America.
• Slight cooling of global temperatures.

To know more about El Niño click here

Recent warnings of WMO

• Noted that unusually warm subsurface ocean temperatures—more than 6°C above average in some areas—are fueling the warming trend.
• Recent sea surface temperatures are rising toward El Niño thresholds, indicating the phenomenon is approaching.
• 80% chance of El Niño developing between June and August.
• El Niño can last from a few months to two years.
• It increases the likelihood of extreme weather worldwide.
• Warm Pacific Ocean temperatures are driving its development.
• The UN warns it could intensify the impacts of climate change.

Reference

The Indian Express| El Nino