Understanding El Niño

A recurrent weather phenomenon

El Niño
El Niño
25 MAR 2016
by

The El Niño weather phenomenon has been observed as becoming more intense over the past decades. Its impacts are even exacerbated by global warming.

The 2015-2016 El Niño has substantially influenced weather patterns across the globe. Its impacts already include massive wildfires in Indonesia, droughts in many regions, and a record number of hurricanes in the Pacific.

But what exactly is El Niño?

El Niño is a recurrent weather phenomenon. It is characterized by a warming of the surface waters in the equatorial zone of the central and Eastern Pacific Ocean. This means that the usual pattern in the atmospheric circulation and tropical precipitation is disturbed by the warmer than normal sea surface temperatures. El Niño also causes constant changes in the wind and rainfall, and it brings about extreme climatic events throughout the world, such as drought, flash floods, and extreme hurricanes.

The warmer surface air pressures particularly occur in Southeast Asia, including Indonesia and the Philippines, and Australia. These areas experience drier conditions or droughts. Dry conditions also occur in some parts of Africa, Hawaii, northeastern Brazil, and Colombia. Meanwhile, lower pressures prevail over the central and eastern Pacific, some parts of South America, west coast of South America, and the southern parts of the United States during winter. These lower pressures bring about heavy rains and flooding.

An El Niño phenomenon normally occurs approximately every two to seven years, and may last between 12 and 18 months. It peaks around Christmas. But despite its periodic and recurrent character, an El Niño does not have a deterministic trend. This means that it does not have a fixed period of occurrence. Its intensity is very difficult to predict, too.

Scientists observed that each El Niño episode is becoming more intense over the past few decades. In fact, they reported that we are now experiencing an intense episode, which they call the third “super” El Niño. Historically, there have only been two “super” El Niños recorded. Until now. These occurred in 1982-1983 and 1997-1998.

El Niño and global warming

Another factor that have substantially contributed to the heightened intensity of El Niño is global warming. Temperatures in 2015 have already soared record high that severely disrupted agriculture, fisheries, the environment, and energy demand. Human health is put at risk, too.

The drought’s impact on agriculture poses threat of global food insecurity. That’s why in Southeast Asia, particularly in the Philippines, citizens are encouraged to plant crops on their backyard or immediate surroundings to minimize the shortage of vegetables and other food products in the market. It is also meant to prepare the people for further possible unusual effects of the El Niño.

Although, the National Oceanic and Atmospheric Administration (NOAA) predicts that El Niño will return to a neutral condition by the second quarter of 2016, it also warns that the affected regions will still continue to receive a below average precipitation during the rainy season. The South and Southeast Asian regions will still have drought in the coming weeks. While the North-Western Pacific will continue to experience stronger cyclones, and the South Pacific with more frequent cyclones.

Historically also, based on previous patterns, an El Niño episode is likely to be followed by La Niña, or the cold phase of the El Niño-Southern Oscillation (ENSO). And should this happen, conditions in countries that have been hit by El Niño will be exacerbated.

To wrap all this up, it’s really of great advantage to strive to understand El Niño. This way, we would be able to act accordingly to help slow down climate change.