The ENSO (El Niño-Southern Oscillation) cycle plays a crucial role in shaping global weather patterns, particularly the Indian monsoon. However, recent anomalies in sea surface temperatures (SST) and wind patterns in the Pacific Ocean have created uncertainty regarding whether 2025-26 will be an El Niño or La Niña year. This ambiguity raises concerns about the reliability of monsoon forecasts, which are critical for India’s agriculture and economy.
Relevance : GS 1(Geography )
- Confusion in ENSO State:
- Sea Surface Temperature (SST) anomalies in the Pacific are not following typical El Niño or La Niña patterns.
- Unusual cold SST anomalies in central-western Pacific and warm SST anomalies in far eastern Pacific.
- Historically, La Niña is associated with cold SST in the eastern Pacific, but this pattern is unclear.
- Implications for India’s Monsoon (2025-26):
- ENSO impacts only about 60% of monsoon deficit/surplus years.
- Uncertainty in 2025 monsoon forecasts due to mixed signals from SST and wind patterns.
- Indian Ocean Dipole (IOD) may counteract the ENSO effect, as seen in 2023.
- Forecasting Challenges:
- February 2025 forecasts give conflicting signals—some models predict La Niña by fall, others indicate normal conditions, and one suggests an El Niño.
- The ENSO transition mode (ETM) in the Southern Hemisphere may have prevented the strong La Niña initially expected for 2024.
- Impact of Climate Change:
- Global warming is altering typical El Niño and La Niña behavior.
- Mid-latitude temperature changes, influenced by shifting jet streams, are affecting monsoons and pre-monsoon cyclones.
- Early heat waves in 2025 add another layer of uncertainty.
- Policy and Preparedness:
- India’s agricultural sector remains vulnerable to unpredictable monsoon patterns.
- Governments and meteorological agencies must improve forecast reliability.
- Need for adaptive strategies to manage climate risks, including droughts and extreme weather.
Conclusion: The ENSO state remains uncertain, making monsoon forecasts challenging. While researchers continue to analyze trends, policymakers and farmers must brace for any outcome.
