El Niño

Climate pattern in the Pacific Ocean

El Niño is a complex weather pattern resulting from variations in ocean temperatures in the Equatorial Pacific. It is part of a larger phenomenon known as the El Niño-Southern Oscillation (ENSO), which includes both El Niño and its counterpart, La Niña. El Niño is characterized by the warming of sea surface temperatures in the central and eastern Pacific Ocean, which can have significant impacts on global weather patterns.

Characteristics

El Niño events are typically marked by the following characteristics:

• Warming of sea surface temperatures in the central and eastern Pacific Ocean.
• Changes in atmospheric pressure patterns, known as the Southern Oscillation.
• Altered weather patterns, including increased rainfall in the Americas and drought conditions in Australia and Southeast Asia.

Causes

El Niño is caused by the weakening of the trade winds that normally blow from east to west across the Pacific Ocean. This weakening allows warm water from the western Pacific to move eastward, disrupting the normal upwelling of cold, nutrient-rich water along the coast of South America.

Impacts

The impacts of El Niño can be far-reaching and include:

• Increased rainfall and flooding in the Americas, particularly in Peru and Ecuador.
• Drought conditions in Australia, Indonesia, and other parts of Southeast Asia.
• Altered hurricane activity in the Atlantic Ocean.
• Changes in marine ecosystems, including shifts in fish populations.

Monitoring and Prediction

El Niño events are monitored and predicted by various meteorological organizations, including the National Oceanic and Atmospheric Administration (NOAA) and the World Meteorological Organization (WMO). These organizations use a combination of sea surface temperature data, atmospheric pressure readings, and computer models to forecast the onset and intensity of El Niño events.

Historical Events

Some notable El Niño events include:

• The 1982-1983 El Niño, which caused severe weather disruptions worldwide.
• The 1997-1998 El Niño, one of the strongest on record, leading to widespread flooding and droughts.
• The 2015-2016 El Niño, which had significant impacts on global weather patterns and agricultural production.

See Also

• La Niña
• El Niño-Southern Oscillation
• Trade winds
• Southern Oscillation
• National Oceanic and Atmospheric Administration
• World Meteorological Organization