Q.11 The abnormal warming of surface ocean water in eastern pacific is called
- La Nina
- El Nino
- La Nino
- El Nina
El Niño refers to the abnormal warming of surface ocean water in the eastern Pacific. The correct answer is El Nino.
Option Analysis
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La Nina: Incorrect. This is the opposite phase, involving cooling of eastern Pacific surface waters (by ≥0.5°C below average for 5 months), strengthening trade winds, and pushing warm water westward.
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El Nino: Correct. Defined as warming of eastern/central Pacific sea surface temperatures (≥0.5°C above average for 5+ months), weakening trade winds, and shifting warm water eastward, disrupting global weather.
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La Nino: Incorrect misspelling/variant of La Niña; no scientific recognition as a distinct phenomenon.
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El Nina: Incorrect hybrid/misspelling; combines elements but does not exist in ENSO terminology.
Introduction to Abnormal Warming Eastern Pacific El Nino
Abnormal warming eastern pacific El Nino marks the warm phase of ENSO, raising sea temperatures off South America and altering global climate. Unlike La Nina cooling, it triggers floods, droughts worldwide.
El Nino Mechanism
Normally, trade winds push warm water west, upwelling cold water east. During El Nino, winds weaken, warm pool shifts east, raising temperatures 2-4°C, boosting evaporation and storms.
La Nina Contrast
La Nina intensifies winds, cooling eastern Pacific, causing opposite effects: U.S. northern wet, southern dry; more Atlantic hurricanes.
Phase Sea Temp Eastern Pacific Trade Winds U.S. Winter Impact El Nino Warming (+0.5°C+) Weakened Southern wet, northern dry La Nina Cooling (-0.5°C-) Strengthened Northern wet, southern dry Global Impacts
El Nino links to India droughts, Peru floods, Australian heatwaves. Lasts 9-12 months, peaks winter; monitors via NOAA ONI index.
Detection and Prediction
Satellite data, buoys track anomalies. 2023-24 El Nino faded to neutral by mid-2025.
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