Neutral Conditions to Dominate the Pacific Ocean

Context

Recently, the National Oceanic and Atmospheric Administration (NOAA) has forecasted that neutral conditions will dominate the Pacific Ocean until October 2025.

Key Highlights

• It highlights the absence of El Niño or La Niña phenomena, together referred to as the El Niño-Southern Oscillation (ENSO).
• The NOAA report suggests that the fast and susceptible La Niña observed in advance this year has transitioned into neutral conditions.
• Sub-surface temperatures in the Pacific have normalized, signaling the end of La Niña.

About El Niño-Southern Oscillation (ENSO)

• It is an evidently occurring climate phenomenon due to interactions between the ocean and atmosphere in the equatorial Pacific Ocean. It has three phases:
• El Niño: It is a clearly happening weather sample associated with the warming of the ocean surface temperatures in the significant and eastern tropical Pacific Ocean.
  • It occurs irregularly at 2 to 7 year intervals.
• La Nina: It is characterised by cooler than common ocean surface temperatures in the relevant and eastern tropical Pacific Ocean.
  • During La Niña events, trade winds are even stronger than standard, pushing more warm water closer to Asia.
• Neutral: Neither El Niño nor La Niña conditions dominate.
  • Neutral conditions occur while ocean surface temperatures inside the equatorial Pacific Ocean continue to be near the long-term average.

Key Components of ENSO

• • El Niño
    • Suppresses rainfall in Australia, Indonesia, and India.
    • Increases rainfall and flooding inside the southern US and Peru.
    • Typically weakens the Indian Monsoon and increases storm activity in the Pacific.

• La Niña

• • • Strengthens monsoons in South Asia.
    • Brings drought to the U.S. Southwest.
    • Causes increased Atlantic hurricane activity.

• Southern Oscillation

• • Refers to the atmospheric element of ENSO.
  • Measured by the Southern Oscillation Index (SOI), which tracks pressure variations between Tahiti and Darwin, Australia.

Impact on Global Weather  

• Global Implications: Neutral conditions reduce the chance of extreme weather activities related to El Niño or La Niña, which include droughts or floods.
  • However, localized weather anomalies may also still arise because of different climatic factors.
• India’s Southwest Monsoon: ENSO-impartial conditions are typically related to everyday or above-normal rainfall in the course of India’s monsoon oceanson.
  • It  is a positive development for agriculture, as almost 70% of India’s annual rainfall happens between June and September.

Future Outlook  

• Forecast Accuracy: NOAA predicts a 50% threat of ENSO-impartial conditions persisting through August-October 2025.
  • IMD is expected to launch its Long Range Forecast for the monsoon oceanson soon, incorporating these findings.

Monitoring ENSO: Continuous monitoring of ocean surface temperatures and atmospheric patterns is important for early detection of any shifts towards El Niño or La Niña.

Source: The Indian Express

Mains PYQ

Drought has been recognized as a disaster in view of its spatial expanse, temporal duration, slow onset and lasting effects on vulnerable sections. With a focus on the September 2010 guidelines from the National Disaster Management Authority (NDMA), discuss the mechanisms for preparedness to deal with likely El Nino and La Nina fallouts in India? (2014)

Download as PDF