Question

La Niña is a phase of the El Niño Southern Oscillation (ENSO), a climate phenomenon characterised by changes in sea temperatures along the central and eastern tropical Pacific Ocean, accompanied with fluctuations in the atmosphere overhead. ENSO influences, alters, and interferes with global atmospheric circulation, which, in turn, influences the weather worldwide. In India, El Niño is associated with decreased rainfall and higher temperatures, while La Niña is associated with increased rainfall and hence lower temperatures.

What would be the impact of La Niña on the seasons in India?

Answer 1

La Niña intensifies the South-West Monsoon in India, producing cooler and wetter conditions.

1. Temperature: Mean seasonal temperatures fall. Heatwaves become less frequent and daytime temperatures decrease.
2. Pressure: Strengthened cross-equatorial winds and lower surface pressure over the Indian Ocean enhance the monsoon circulation. Anomalously low pressure over the core monsoon region increases the inflow of moisture.
3. Precipitation: India generally receives above-normal rainfall, with more frequent heavy spells and an increased risk of floods, especially in central and northern India.
4. Seasonal Effects: The South-West Monsoon may arrive earlier or become stronger, with longer active phases. This improves crop prospects but also increases the risk of floods and landslides.