Sambhav-2025

Approach Briefly define El Niño and La Niña. Discuss the impact of these phenomena on the Indian Monsoon. Conclude suitably.

Introduction

El Niño and La Niña are climatic phenomena associated with the El Niño-Southern Oscillation (ENSO), characterized by temperature anomalies in the Pacific Ocean. These phenomena significantly affect India's monsoon circulation.

Body

Impact of El Niño on Monsoon:

• El Nino is a climate pattern that describes the unusual warming of surface waters in the eastern tropical Pacific Ocean.
• It is the “warm phase” of a larger phenomenon called the El Nino-Southern Oscillation (ENSO)
• El Niño involves oceanic and atmospheric phenomena with the appearance of warm currents off the coast of Peru in the Eastern Pacific, which weakens the trade winds and the Walker Circulation. This reduces the moisture-laden winds reaching India.
• In India, El Niño generally tends to weaken the monsoon, resulting in drier-than-average conditions and reduced rainfall. This can lead to droughts, water shortages, and agricultural losses.
• The 2015 El Niño led to a monsoon deficit of 14%, causing widespread agricultural distress.

Impact of La Niña on Monsoon:

• La Nina, the “cool phase” of ENSO, is a pattern that describes the unusual cooling of the tropical eastern Pacific.
• In the La Niña phase, trade winds strengthen, pushing larger volumes of water toward the western Pacific, leading to cooler temperatures in the eastern Pacific.
• It results in above-normal rainfall, which can lead to floods in some regions while benefiting water reservoirs and agriculture in others.
• The most recent La Nina phase lasted from 2020 to 2023.

Conclusion

Monitoring El Niño and La Niña phenomena are vital for predicting monsoon variability in India. It aids in disaster preparedness, agricultural planning, and water resource management, ensuring better resilience against climate-induced challenges.