The Weather Man

During the past several years, the climate event known as El Niño has been one of America's biggest scapegoats. Flooding in the Midwest was attributed to El Niño. The hurricanes in the Carolinas had to be from El Niño. And the earthquakes in California? That was probably El Niño, too, right?

Contrary to popular belief, El Niño is not just the big, bad weather monster that destroys crops and levels cities.

Just ask University professor S. George Philander, chair of the geosciences department.

This summer, Philander — along with geoscientist Alexey Fedorov — published an article in the June 16 issue of Science magazine that discusses El Niño, its causes and its effects.

"It's probably the biggest climate fluctuation we have other than the changing of the seasons," Philander said as part of his explanation of El Niño. "It affects weather globally."

Many people became familiar with the phenomenon after its 1997 episode, which — along with its occurrence in 1982 — was one of its most extreme cases in more than a century.

The article discusses Philander's research and his theories on El Niño.

In trying to explain why El Niño occurs at all, Philander drew on a familiar example. "It's a little like asking why a pendulum swings back and forth," he said.

El Niño is one of the two parts to what is known as the Southern Oscillation, which is a natural phenomenon that refers to the fluctuation of pressure from high to low, or vice versa, over the eastern and western tropical portions of the Pacific Ocean.

"The Pacific is so vast that if you warm the Pacific, it affects weather globally," Philander explained.

And El Niño does just that. Through interactions between the ocean and the atmosphere — and as a result of the warmer layer of ocean water in the Pacific that sits above the deeper, cooler layer — El Niño forms clouds, winds and weather patterns that travel throughout the world.

Get the best of the ‘Prince’ delivered straight to your inbox. Subscribe now »

"For a long time, people thought of El Niño as a sporadic [change in the regular patterns of climate]," Philander explained. This is, however, not true.

El Niño occurs in only one phase. Recently, scientists have discovered that there is a second phase that forms a complete cycle with the phenomenon.

The early name given to this compliment was "anti-El Niño." Though the actual translation of the Spanish phrase "el niño" is "the boy," most regard the capitalized form to mean "child Jesus." Thus, the term "anti-El Niño" had connotations of the anti-Christ.

To avoid using any offensive jargon, Philander started to use the phrase "La Niña," or "the girl," which he said seems like a natural choice.

"It's certainly better than anti-El Niño," he added. "That's a terrible name." And — despite the fact that Philander received a number of angry letters — La Niña stuck.

Over time, La Niña cools the eastern tropical region of the Pacific, effectively bringing the cycle back to where it was before El Niño began.

Whereas El Niño is a shorter cycle and tends to have more intense global effects, La Niña is the longer and milder part of the cycle.

"The common mistake is to think that El Niño is a departure from the normal," Philander said.

Because the Southern Oscillation is constant, one of the two patterns is always occurring. In fact, the changes in pressure and temperature that occur during El Niño cause La Niña, which in turn causes El Niño, and so on. Determining which came first, Philander said, is akin to the chicken and the egg conundrum.

Though scientists have learned much about the phenomena in recent years, the cycle of the Southern Oscillation appears to be changing somewhat.

While the Southern Oscillation usually has been a four-year period, the past few episodes of El Niño have taken place five years apart.

Philander returned to the pendulum analogy to explain the change. "If you shorten the pendulum, it will swing much faster," he said.

What is happening, Philander theorizes, is that the proverbial pendulum is lengthening, causing it to swing more slowly and the cycle to become longer.

While Philander examines in his article the possibility that these recent changes are simply statistical blips of nature, he supports the idea that it is part of a gradual changing in the pattern. And he predicts that the next El Niño episode will not occur until 2002.

The article also grapples with the causes of what would appear to be a rather sudden shift.

There are many factors, according to Philander, that affect the Southern Oscillation, such as trade winds and differences in temperature. However, these properties are constantly changing at a very gradual pace.

Now the properties have changed so much that the cycle has been lengthened a little.

One popular theory is that the cyclical changes were caused by global warming.

"I can't exclude it," Philander said, noting that oceanic temperature is one of the factors that affects El Niño.

Philander, not unlike many other scientists in his field, started out as a mathematician. "I studied applied mathematics," he said. "You have to apply it to something."

But why apply it to El Niño?

A number of factors led Philander into his studies, he explained.

While completing his graduate work at Harvard University, Philander found that many of his professors and friends were becoming interested in studying the ocean and its properties.

Because changes in ocean conditions occur so quickly at the equator, Philander said, this became a target area for the study of winds, the gulf stream, temperature fluctuations and the like.

At the same time, a geosciences field that combines mathematics, oceanography, meteorology and geology was becoming more and more popular. "Initially, it was a much more cozy field," Philander noted. But the number of scientists studying in the field was doubling every five years, and Philander decided that he wanted to be part of it.

"Over the last 20 years, we turned our attention to the problem [of El Niño]," he said.

People want to learn about El Niño for the same reason they want to know the daily weather, Philander explained. "You very much want to know if the winter will be extremely mild or extremely cold."

Predicting El Niño — like predicting the daily weather forecast — has a very large commercial interest. Daily weather is a big business, Philander said, and forecasting El Niño and other weather fluctuations is its long-term counterpart.

Predicting El Niño's next occurrence is useful in helping to curb the losses that have been suffered in the past. Knowing when to expect El Niño will allow would-be victims the chance to prepare.

Philander's 1990 book, "El Niño, La Niña, and the Southern Oscillation," discusses these weather phenomena in detail.

"Is The Temperature Rising? The Uncertain Science of Global Warming," Philander's 1998 book, also contains a section on El Niño. In addition to his books, he has also written and published about 100 articles on the subject in various science journals.

Though he continues his work with El Niño, Philander is studying other significant climate changes of the past, such as the Ice Ages. He said that unlocking the answers to these past events will lend credibility to the field of geoscience in its future predictions.

"Why should you believe what I say about global warming," he asked, "if I can't explain why that happened in the past?"