La Nina, Spanish for ‘little girl’, is the cool counterpart of El Nino (‘little boy’). Together, they form the El Nino–Southern Oscillation (ENSO), a cycle that swings between warm, neutral and cool phases in the central and eastern tropical Pacific Ocean, according to a National Geographic report.
How Does It Happen?
La Nina begins when unusually strong easterly trade winds push cold subsurface waters to the Pacific’s surface in a process called upwelling. This, in turn, leads to sea-surface temperatures dropping by at least 0.5 degrees Celsius below normal levels for several overlapping three-month periods.
How Did It Derive the Very Name?
The Spanish names stem from observations by fishermen off Peru and Ecuador. El Nino refers to warm waters that typically appear around Christmas, while La Nina represents the opposite of it: a cooling, “anti–El Nino” effect, per the World Meteorological Organization.
What Effects Does It Have?
La Nina, reports suggest, is known to flip climate patterns globally:
- Southeast Asia and Australia see increased rainfall, which, in some cases, trigger floods.
- Northern Brazil and southeastern Africa tend to be wetter than usual, while parts of South America’s west coast, the Gulf Coast, and the southern US, get drier conditions.
- The phenomenon boosts fishing off South America by bringing nutrient-rich, cold waters to the surface, the report said.
- In India, however, La Nina typically strengthens the monsoon, often helping agriculture but it can also cause flooding, reports suggest.
- In the US, La Nina can mean cooler, wetter winters in the north, and warmer & drier conditions in the south.
How Long Does It Last?
La Nina usually lasts between 9 months and a year, but some events, especially stronger ones can even stretch up to two years or more. According to the US federal climate agency’s estimates, scientists have recorded a growing number of multi-year events, including a rare triple-dip La Nina from 2020 to 2023 .
Why It Might Matter Now
The triple-dip La Nina of 2020–2023 intensified droughts and floods worldwide – even as it failed to break a streak of record-breaking hot years, underscoring that La Nina, despite its cooling trends, occurs amid a larger human-driven warming trend, which continues to push global temperatures to new highs.
