Prelims 2011 · archive
EasyLa Nina is suspected to have caused recent floods in Australia. How is La Nina different from El Nino?
- 1.La Nina is characterized by unusually cold ocean temperature in the equatorial Indian Ocean whereas El Niño is characterized by unusually warm ocean temperature in the equatorial Pacific Ocean.
- 2.El Nino has adverse effects on the south-west monsoon of India, but La Niña has no effect on monsoon climate.
Which of the statements given above is/are correct?
Answer & explanation
Answer: (d) Neither 1 nor 2
Both statements are wrong. La Niña is a cooling of the equatorial Pacific Ocean, not the Indian Ocean. It also influences the Indian monsoon, usually by strengthening it.
- ✗ 1. La Niña is unusually cool sea surface temperature in the central and eastern equatorial Pacific Ocean. This is the same region where El Niño brings unusual warming. La Niña is not defined over the Indian Ocean, which has its own separate phenomenon, the Indian Ocean Dipole.
- ✗ 2. El Niño does generally weaken the south-west monsoon and often brings below-normal rain. But La Niña also affects the monsoon. It generally strengthens the monsoon circulation and raises the chance of above-normal, more widespread rainfall and floods.
Remember · ENSO is a Pacific phenomenon. El Niño is warm and usually weakens the Indian monsoon. La Niña is cool and usually strengthens it.
Sources
- IMD – FAQ: ENSO, IOD and its Impact on Indian Summer Monsoon Rainfall ↗ “La Niña: Unusually cool sea surface temperatures over the same region. … La Niña generally strengthens the monsoon circulation and increases the likelihood of: 1. Above-normal monsoon rainfall 2. More widespread rainfall 3. Increased flood potential … El Niño: Unusually warm sea surface temperatures over the central and eastern equatorial Pacific Ocean.”
Question: UPSC Civil Services (Preliminary) 2011, General Studies paper. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). ·