Volcanic eruptions can trigger El Niño events, study reports

A new study shows volcanic eruptions in the tropics can shift climate change by causing large El Niño events.
By Ed Mason | Oct 05, 2017
Strong tropical volcanic eruptions can trigger warming periods in the Pacific Ocean known as El Nio events, according to recent research published in the journalNature Communications.

El Nio events are concerning to scientists because they shift temperatures and alter climate patterns across different parts of the world. While they happen in different ways, volcanic eruptions trigger the events bypumpingmillions of tons of sulfur dioxide into the stratosphere. That then forms sulfuric acid clouds, which reflect solar radiation and reduce the average global surface temperature.

A team of scientists from Rutgers University made this discovery by running a number of sophisticated climate model simulations to show that El Nios typically peak the year after large volcanic eruptions, such as the one at Mount Pinatubo in 1991. That information sheds light on the process and could give researchers a new way of anticipating the events.

"We can't predict volcanic eruptions, but when the next one happens, we'll be able to do a much better job predicting the next several seasons, and before Pinatubo we really had no idea," said study co-author Alan Robock, a professor in the Department of Environmental Sciences at Rutgers University-New Brunswick, according to Phys.org. "All we need is one number - how much sulfur dioxide goes into the stratosphere - and you can measure it with satellites the day after an eruption."

Currently, the El Nio Southern Oscillation (ENSO) -- which features sea surface temperatures in both the central and eastern Pacific -- is nature's leading mode of periodic climate variability. ENSO events, which consist of either El Nio or a cooling period known as La Nia, happen once every three to seven years. The processes usually happen at the end of the year and alter atmospheric circulation, which then causes large climate shifts.

While strong events have been known to stop hurricane development in the Atlantic Ocean, they also can elevate sea levels and lead to high winds. In addition, the study shows that El Nio-like patterns have followed four of the five last big tropical volcanic eruptions. Such blasts tend to shortenLa Nias and make El Nios longer.

This information is important because, by being able to better predict weather shifts, officials and citizens will be able to prepare for El Nio events. Most changes happen suddenly and without too much warning. If people know they are coming it can lessen any negative effects.

"If you're a farmer and you're in a part of the world where El Nio or the lack of one determines how much rainfall you will get, you could make plans ahead of time for what crops to grow, based on the prediction for precipitation," added Robock.


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