El Niño,” meaning “The Christ Child,” was coined by fishermen along the coasts of Ecuador and Peru in the early 1960s. It refers to the unusual warming of the central and eastern Pacific Ocean that often occurs around Christmas. This phenomenon arises when the normal pattern of trade winds weakens, disrupting weather systems across the globe.
The Pacific Ocean is generally warmer than other oceans because of consistent solar radiation in the tropics throughout the year. During El Niño, the east-to-west trade winds weaken, causing the warm pool of water in the central Pacific to shift eastward toward the coasts of South America, near Ecuador and Peru.
This movement is influenced by natural ocean currents, Earth’s rotation, and tidal effects. As the warm water moves eastward, the thermocline (the boundary between the warm surface water and the cold, deep water) tilts.
In the eastern Pacific, the warm water creates a low-pressure zone, resulting in heavy rainfall and flooding along the coasts of Ecuador and Peru.
Meanwhile, in the central Pacific, as the warm surface water shifts, colder, nutrient-rich water from the deep ocean rises to the surface in a process called upwelling. This makes the region ideal for fishing, benefiting countries like Japan and the United States, which rely on these nutrient-rich waters to sustain their fishing industries.
On the other side, regions like Australia and Indonesia suffer from severe droughts and bushfires due to the lack of rainfall. For instance, the devastating wildfires in Australia during the 2019–2020 bushfire season and increased fire risks in 2023 were exacerbated by El Niño, Heatwaves in Indian subcontinent. These weather shifts highlight the global impacts of this powerful climate phenomenon.