El Nino is the warm phase of the El Nino-Southern Oscillation (ENSO), characterized by unusually warm sea surface temperatures in the equatorial Pacific Ocean. It influences global weather patterns, including precipitation and drought.
El Nino is a climate phenomenon that occurs when sea surface temperatures (SSTs) in the central and eastern equatorial Pacific Ocean become anomalously warm, typically by 0.5 degrees Celsius or more above normal for an extended period. El Nino events develop irregularly, roughly every 2-7 years, and typically last 9-12 months, though some events persist longer. The warming of Pacific waters alters atmospheric circulation patterns through a coupled ocean-atmosphere interaction known as the El Nino-Southern Oscillation (ENSO), with far-reaching teleconnections that affect weather worldwide. During El Nino, the southern United States tends to experience wetter and cooler conditions, while the Pacific Northwest becomes drier and warmer. Indonesia, Australia, and parts of Africa and South Asia often experience drought during El Nino years. Strong El Nino events can significantly impact global food production, water resources, and natural disasters, with estimated economic costs in the billions of dollars. ENSO monitoring relies on networks of ocean buoys, satellite observations of sea surface temperature, and atmospheric pressure measurements. The opposite phase, La Nina, features cooler-than-normal Pacific SSTs and generally produces inverse climate impacts.