"El Niño Drought Emergency Declared Across Central America and Peru"
El Niño
Periodic warming of central and eastern equatorial Pacific surface waters, disrupting global wind and rainfall patterns.
ENSO
El Niño–Southern Oscillation; the coupled ocean-atmosphere system of which El Niño is the warm phase.
El Niño is a periodic warming of surface waters in the central and eastern equatorial Pacific Ocean. It is part of a larger coupled ocean-atmosphere system called ENSO (El Niño–Southern Oscillation). During an El Niño event, warm water that normally pools in the western Pacific drifts eastward toward the South American coast, replacing cooler upwelling currents such as the Peruvian (Humboldt) Current. This shift disrupts the Walker Circulation, the east-west atmospheric circulation cell over the tropical Pacific, and triggers cascading changes in wind patterns, rainfall distribution, and temperature across the globe.
El Niño events occur on average every two to seven years. Their intensity varies considerably. Moderate events cause regional disruptions; strong events produce widespread agricultural failures, infrastructure stress, and humanitarian crises across multiple continents simultaneously. The Southern Oscillation Index (SOI), measuring the pressure difference between Tahiti and Darwin, is the standard metric used to track ENSO phase and intensity. A strongly negative SOI signals an active El Niño.
For India, El Niño is most consequential because it suppresses the southwest monsoon. Historically, strong El Niño years, including 2002, 2009, 2015–16, and 2023–24, have coincided with significant monsoon deficits and agricultural stress. Over 60% of India's net sown area is rain-fed, making the country structurally exposed to any phenomenon that weakens monsoon delivery.
El Niño disrupts global weather through a well-established atmospheric pathway. Warming of Pacific surface waters weakens the Walker Circulation, reducing the east-west pressure gradient that drives moisture-laden trade winds toward Asia and Africa. This suppresses convective activity over the Indian Ocean and the Bay of Bengal, cutting the moisture supply that fuels India's southwest monsoon. The result is spatially uneven but statistically significant rainfall deficits, particularly over peninsular and central India.
Beyond India, El Niño's global footprint is large. In the Central American Dry Corridor, an arid strip running through parts of Guatemala, Honduras, El Salvador, and Nicaragua, El Niño intensifies already-marginal rainfall conditions. …
In the South Atlantic and South-Eastern Pacific regions in tropical latitudes, cyclone does not originate. What is the reason?
"Each day is more or less the same, the morning is clear and bright with a sea breeze; as the Sun climbs high in the sky, heat mounts up, dark clouds form, then rain comes with thunder and lightning. But rain is soon over."
Which of the following regions is described in the above passage?
Consider the following statements regarding El Niño:
1.It involves warming of surface waters in the central and eastern equatorial Pacific Ocean.
2.It strengthens the Walker Circulation, increasing rainfall over the Indian subcontinent.
3.It occurs on average every two to seven years.
4.Its intensity is tracked using the Southern Oscillation Index, measured as the pressure difference between Tahiti and Darwin.
How many of the above statements are correct?
Consider the following pairs:
Geographic Feature — Relevance to El Niño
1.Gatun Lake — Freshwater source for Panama Canal lock system
2.Central American Dry Corridor — Arid strip covering parts of Honduras, El Salvador, Guatemala, and Nicaragua
3.Peruvian (Humboldt) Current — Warm current that intensifies during El Niño
4.Southern Oscillation Index — Pressure difference between Tahiti and Darwin
How many of the above pairs are correctly matched?
With reference to the Panama Canal, consider the following statements:
1.The canal uses freshwater from Gatun Lake to operate its lock system.
2.El Niño-induced drought reduces Gatun Lake water levels, forcing restrictions on vessel draft.
3.The canal connects the Atlantic Ocean to the Indian Ocean.
Which of the statements given above is/are correct?
The 'Central American Dry Corridor' is sometimes seen in the news. Which of the following best describes it?
Assertion (A): El Niño events are now producing more severe compound extremes than historical analogues would predict.
Reason (R): Anthropogenic climate warming raises the baseline global temperature, so El Niño-driven warming is superimposed on an already warmer system.
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