By Virginia Nowakowski
Contrary to Chris Farley’s infamous 1997 SNL skit, El Niño is not a loudmouthed wrestler. The phrase also does not translate to “The Niño”. El Niño has been the biggest buzzword of the season. It actually means “the Christ child” in English, and it’s weather phenomenon named by South American fishermen who first noticed increased water temperatures during the Christmas holidays in the 1600s. El Niño occurs every two to seven years, wreaking havoc in many climates throughout the world. Here’s what you should know:
What is it exactly?
“El Niño is actually part of something that we in the meteorological community refer to as ENSO, or El Niño Southern Oscillation,” says Professor Daniel Horton, who works in the environmental sciences department at Northwestern. ENSO occurs in the equatorial Pacific Ocean, an area spanning between South America and Australia. During normal years, trade winds, constant eastern winds that dominate the world’s tropics, push warm sea water toward Australia’s side. “Typically in the Pacific Ocean the warmest sea surface temperatures are in the eastern pacific, over near Indonesia,” Horton says. “During El Niño years those warm sea surface temperatures get pushed over into the western equatorial Pacific near the coast of Peru.” The oscillation changes atmospheric circulation and climates around the world with it.
How does it change climates?
Scientists can’t guarantee what effects El Niño will have on different regions’ climates, but they observe past events to predict what will happen from year to year. “Each El Niño event is slightly different than the last. We’re talking about fluids after all; we’re talking about the fluid in the ocean and were talking about the air,” Horton says. The unusual movement of warm seawater in the Pacific makes it easy for cyclones and storms to form. Generally, areas near South America receiving warmer water experience higher temperatures and more precipitation, while droughts hit places like Africa and Australia.
How will it affect Evanston?
“In the Midwest, typically the winters are a little milder, a little warmer than on average,” Horton says. “They’re also a little drier than what we typically experience in a winter in the Midwest.” Evanston’s weather has certainly indicated an El Niño year, with warmer temperatures and very few days of snowfall.
Does global climate change affect El Niño?
Global climate change certainly doesn’t cause El Niño- the phenomenon occurs naturally. However, it can affect the impact El Niño has on the world’s weather. With the build-up of greenhouse gases in the atmosphere, global temperatures have risen, including the temperature of water in the ocean.
“During an event like an El Niño in which the sea temperatures are quite warm, there is a little extra heat that’s there that wouldn’t be there naturally from anthropogenic climate change,” Horton says. “That little extra heat can certainly have an impact on weather throughout the globe…it can be an enhancement of conditions or it can add a little bit more moisture to the atmosphere.”
That could mean more rain and flooding, or an increased number of powerful storms.
El Niño conditions normally run for about a year, according to Horton, so don’t get too comfortable with the warmer winter. Although it hasn’t run its full course just yet, multiple sources agree that the 2015-2016 El Niño will be one for the record books. “It’ll be really interesting to see what will happen with this [El Niño] because its been one of the strongest El Niños that we’ve witnessed,” Horton says.