What a ‘super’ El Niño might mean for India’s monsoon, Pg12

Key Highlights:

• The U.S. National Oceanic and Atmospheric Administration (NOAA) confirmed the formation of El Niño in the equatorial Pacific Ocean.
• There is a 63% probability that this El Niño will strengthen into a "very strong" or "super" event by the northern winter.
• India's June rainfall, as of the 16th, was approximately 35% below normal.
• Historically, "super" El Niño events have been rare, with only a handful crossing the 2°C sea-surface temperature threshold.

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Detailed Insights:

• El Niño is characterized by the periodic warming of the central and eastern equatorial Pacific Ocean, which typically weakens the South Asian monsoon.
• The strength of an El Niño is categorized by the departure of sea-surface temperatures from their long-term average: 0.5-1°C (weak), 1-1.5°C (moderate), 1.5-2°C (strong), and above 2°C (very strong).
• The warming is caused by the weakening of trade winds, creating a feedback loop that amplifies the anomaly.
• Climate change, leading to a warmer baseline ocean, is noted to intensify recent El Niño events.
• El Niño typically starts in spring, peaks in winter, and weakens by the next spring, affecting the middle and later parts of the June-September monsoon season.
• Past "super" El Niño events, such as 1982-83, 1997-98, and 2015-16, caused severe droughts, coral bleaching, and record global temperatures.
• The 1997-98 El Niño paradoxically brought above-normal rains to India due to a strong positive Indian Ocean Dipole (IOD).
• The India Meteorological Department (IMD) indicates that the Indian Ocean Dipole may not be strong enough this year to counteract the El Niño's drying effect.
• Approximately 15 out of two dozen El Niño years since 1950 have resulted in below-normal monsoons for India, with about 10 leading to outright deficiency (below 90% of the Long-Period Average).
• El Niño also redistributes tropical cyclones, generally suppressing Atlantic hurricane activity while making conditions more favorable for hurricanes in the central and eastern Pacific.

Key Concepts Involved:

• El Niño: A climate pattern describing the unusual warming of surface waters in the eastern equatorial Pacific Ocean.
• Indian Ocean Dipole (IOD): An irregular oscillation of sea surface temperatures in the Indian Ocean, influencing regional climate.
• Monsoon: A seasonal prevailing wind in the region of South and Southeast Asia, blowing from the southwest in summer and from the northeast in winter.
• Trade Winds: Prevailing easterly winds that blow in the Earth's equatorial region, crucial for ocean currents and weather patterns.