We know that volcanic eruptions can cause some pretty devastating results, and that’s putting it lightly. From destroying entire cities to bombarding the planet with rock and lava, the effects can be devasting. In fact, the most powerful volcanic eruption unleashed an astonishing 5,000 times more energy than our most powerful nuclear weapon.
The fiery mountains can also have an incredible impact on the climate too, as new research has found that volcanic eruptions in the tropics might be enough to trigger the start of the climatic phenomenon known as El Niño. This weather event typically occurs in the eastern Pacific and can trigger a whole host of effects worldwide, from droughts in Australia to monsoons in Africa.
The researchers of the study, published in Nature Communications, used climate model simulations to show how the warm phase of the El Niño Southern Oscillation seemed to peak in the year following a large volcanic eruption, such as when Mount Pinatubo blew its top in the Philippines in 1991.
“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,” says co-author Alan Robock of Rutgers University-New Brunswick in a statement. “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.”
The team note that when the volcanoes eject their masses of ash and debris into the air, they also fill the atmosphere will large volumes of sulfur dioxide. This forms a highly reflective layer of sulfuric acid, reflecting solar radiation and reducing surface temperatures. This reduces the temperature gradient across the Pacific, weakening trade winds and helping to influence the development of El Niño.
Further digging found that since 1882, four of the five biggest eruptions were followed by El Nino-like patterns in sea surface temperatures.
In fact, Robock says that the pattern is so consistent that if there was a volcanic eruption in the tropics tomorrow, he would be able to make predictions about not only the appearance of El Nino the following year, but also seasonal temperatures and rainfall patterns. This, he says, could be crucial information if you happen to rely on the land that El Nino impacts most severely.
“If you're a farmer and you're in a part of the world where El Niño 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,” explains Robock.