News: January 2025 recorded the highest global temperatures for any January on record, with the global average surface air temperature rising 1.75°C above pre-industrial levels (1850-1900 average), according to Europe’s Copernicus Climate Change Service (C3S).
About La Niña
- La Niña is a climatic phenomenon and one of the three phases of the El Niño-Southern Oscillation (ENSO) cycle.
- It is characterized by cooler-than-average sea surface temperatures in the central and eastern tropical Pacific Ocean.
- ENSO operates in three phases, each influencing global weather patterns differently:
- Neutral Phase – Normal oceanic and atmospheric conditions prevail, with trade winds pushing warm waters towards the western Pacific.
- El Niño (Warm Phase) – Trade winds weaken, causing warm water to spread across the central and eastern Pacific, leading to increased global temperatures.
- La Niña (Cool Phase) – Trade winds strengthen, pushing warm waters further west, resulting in cooler oceanic temperatures and generally lower global temperatures.
Impact on Ocean and Atmosphere
- Trade winds strengthen, pushing more warm water towards Asia.
- Increased upwelling occurs off the west coast of the Americas, bringing cold, nutrient-rich water to the surface.
- The jet stream shifts northward, altering weather patterns significantly.
Impact on Weather Patterns
- Northward shift of the jet stream: It leads to drought in the southern U.S.A and heavy rains and flooding in the Pacific Northwest and Canada.
- Winter Temperature Effects: Warmer than normal in the southern U.S.A. and cooler than normal in the northern U.S. and Canada.
- Hurricane Season: La Niña can lead to a more intense and active hurricane season.
Impacts on Marine Life
- Colder Pacific waters during La Niña contain more nutrients.
- This attracts cold-water species like squid and salmon to coastal areas such as California.
- Marine ecosystems flourish due to the increased availability of nutrients.
