Explore Magazine Volume 3 Issue 2


"El Nino": No Angel

University of Florida researchers focus on many diverse aspects of the enigmatic weather phenomenon

Cesar Caviedes has never forgotten the real-life implications of El Niño that he witnessed growing up in the coastal city of Valparaiso, Chile.

"For us central Chileans, the El Niño years of 1957, 1958 and 1965 meant more rains, more birds dying on the beach and less fish to eat," says Caviedes, chairman of the University of Florida's geography department. "For me, El Niño was a life experience long before it became a scientific concept."

When Caviedes published his first El Niño paper in 1969, he was practically alone in discussing what by 1998 Time magazine was calling "the most studied weather phenomenon of all time."

"Cesar Caviedes deserves a tremendous amount of credit for waving the flag about the ecological impact of El Niño in the 1970s," says UF botanist Stephen Mulkey. "No one listened then, but he was right."

Caviedes recalls being one of about a dozen scientists who met to discuss El Niño at the Scripps Institution of Oceanography in San Diego, California, in the summer of 1975.

"Today, thousands of researchers attend El Niño meetings," he says, laughing. "Even meetings of the most esoteric sub-disciplines have hundreds of attendees."

Caviedes is the elder statesman of what he calls an internationally "well-respected, very productive core" of El Niño researchers at UF.

"People who know about El Niño always call us to participate in the top conferences," Caviedes says.

An eclectic researcher whose publications cover social, political and natural issues of South America, Caviedes' El Niño research has always been driven by the weather system's impact on people and their activities.

He says that while academic and public interest in El Niño has grown dramatically and technological advances have given scientists new tools for tracking the phenomenon, understanding the social impacts of El Niño has not kept pace.

"Perhaps because from early on El Niño meant to me a human experience, I have insisted on bringing to light the human implications of El Niño," he says. "We have reached a stunning level of precision and sophistication in describing and quantifying the numerous parameters of the ENSO (El Niño Southern Oscillation) across the planet. But we are incredibly behind in properly surveying the social effects of El Niño on deprived families."

Knowledge Is Power

UF geography Professor Peter Waylen says the massive hydroelectric plants that supply much of Latin America's electricity are "like giant ocean liners, you can't just turn them around on a dime."

So plant operators need plenty of advance warning when a weather phenomenon like El Niño rises out of the ocean like an iceberg, or their country's electrical needs can take a Titanic dive.

That's what happened in 1992, when El Niño-induced droughts left reservoirs well below operational levels and forced residents of countries like Costa Rica, Colombia and Panama to endure rotating blackouts for months.

More than half of the power supply for these three countries comes from hydroelectricity. Waylen says Costa Rica and Panama each rely on one gigantic reservoir to produce more than 30 percent of their hydro power.

During a normal year in this region of Latin America, heavy rain from June through October causes the reservoirs to swell with water that turns the turbines to create electricity. During an El Niño year, however, rainfall can drop by 40 percent or more.

So Waylen and his colleagues developed a computerized "lookout" that uses historical comparisons between eastern Pacific Ocean temperatures and water flow in the rivers and streams that feed the reservoirs to predict reservoir conditions six to 12 months in advance.

Now the researchers are adding a financial component to their model in an effort to convince power plant managers that these computer-generated predictions can save money and prevent service outages.

By crunching millions of bits of data about sea surface temperatures, stream flows and energy purchase costs, the team is trying to close an information gap between scientists and users.

"I think this model will be one of the first times a forecast can be translated into economic costs," Waylen says. "In the past, decisions to conserve the water supply were based simply on experience and estimations. We have to prove that these predictive models are worth using."

Waylen says a pilot study in Colombia estimated the country could have saved $100 million to $150 million if this system had been available during the last El Niño.

"That's money that could have been used for other social services," Waylen says. "And, the people wouldn't have had to go through the blackouts."

The model also could be applied to the 13 percent of energy in the United States derived from hydroelectricity.

"If we increase our efficiency in hydro power by just 1 percent, we could save 4.9 million barrels of oil," he says. "That is $90 million for every 1 percent in increased efficiency."

Waylen has been working on the project with engineering professors from the National University of Colombia at Medellin, the head of the hydrology branch at the Costa Rican Electricity Institute and the head of the hydro-meteorology department at the Institute for Hydrologic Resources and Electrification in Panama.

Modeling A Market

Drowned potato plants, rows of buckled corn stalks, ruined cabbage fields: El Niño's torrential rains and powerful storms inundated Florida vegetable farmers last winter. Then, months of drought left crops gasping for water.

But thanks to computer crop models being developed by a team of researchers from three state universities, farmers may be better prepared for future El Niños.

The researchers intend to use the models -- as well as historical data on crop yields and prices -- to help farmers pick what crops to plant, when to plant and how to manage crops months before El Niño or related La Niña (cold-ocean) events strike. The result for consumers could be more stable prices despite wildly unusual weather.

"If the climate forecasters can predict an El Niño three to six months ahead of time, then agriculture decisions might be changed to take advantage of that situation and reduce risks and uncertainties," says Jim Jones, an agricultural and biological engineering professor at the University of Florida.

Supported by the National Oceanographic and Atmospheric Administration (NOAA) and the National Science Foundation, the project involves researchers at UF, Florida State University and the University of Miami.

An initial step was to gauge how past El Niños or La Niñas have affected crops in Florida and the Southeast, Jones says.

Jim Hansen, a researcher at UF, scrutinized records back to 1929 to measure the impact of past El Niños and La Niñas on vegetable, sugar cane and citrus yields in Florida. He also studied the systems' impact on peanuts, tomatoes, cotton, tobacco, field corn and soybeans in Florida, Alabama, Georgia and South Carolina.

The good news is, some crops were untouched. Florida's orange harvest, for example, did not vary significantly in the years following El Niños of La Niñas, even though orange trees flower in winter, when the weather systems' effects are most pronounced.

Other crops, however, were greatly affected. Yields of tomatoes, bell peppers, sweet corn and snap beans plunged during the winter harvest in Florida in El Niño years, Hansen found. Yields of bell peppers sank 31 percent below the long-term average, while yields for sweet corn sank 27 percent. A likely cause is excessive rainfall, which limits sunlight and promotes disease by saturating plants, Hansen says.

The plunge in vegetable yields was accompanied by increases in prices paid to farmers, Hansen found. Prices for bell peppers, for example, were 31 percent higher, while snap beans were 21 percent higher.

The record-setting 1997-98 El Niño was no different. The state Department of Agriculture and Consumer Services estimated crop damage from flooding at more than $100 million. In addition to reduced cabbage, potato and corn harvests, as much as 75 percent of the strawberry crop was destroyed and even hay for livestock was flooded out.

The computer models can combine weather and soil information with virtual farming decisions to predict growth and yield for crops, Jones says.

"It takes maybe a second or less to grow crops on a PC, so we grow many, many crops to look at the probabilities under different weather predictions ... then we can change management practices to see what effect that will have," Jones says.

While the idea is to give farmers the information they need to map out a growing strategy tailored to the characteristics of a predicted El Niño or La Niña, that strategy also is dictated by market forces, Jones says.

For example, some farmers may steer clear of tomatoes if they expect a predicted El Niño could damage the crop, but others may plant more tomatoes than usual, speculating prices will go up.

Rainforest Or Sunforest?

More than a decade of observing the effects weather -- including two El Niños -- has on tropical rainforests has led UF botanists Stephen Mulkey and Kaoru Kitajima to hypothesize that, contrary to conventional wisdom, sunlight may have the greatest influence on rainforest health.

Now Mulkey, Kitajima and their colleagues at the Smithsonian Tropical Research Institute (STRI), a branch of the Smithsonian Institution, are lighting up the Panamanian rainforests to try to prove their hypothesis.

Historically, rainforest health has been tied to nutrients in the soil or the availability of water, especially during the dry season. But after observing the effects of El Niño from atop a 17-story crane in Panama's Atlantic rainforest, Mulkey and his colleague, S. Joseph Wright at STRI, argue available sunlight may be the most influential factor.

"What tipped us off was the abnormally strong and unusually placed El Niño last year," Mulkey says. "This El Niño actually arrived at the beginning of Panama's rainy season, resulting in much more sunlight during a time when it would normally be overcast and rainy."

The result was trees making fruit two and even three times as often as normal. Those observations jibed with more than a decade of data Mulkey and Wright had collected.

"Since 1987, STRI has maintained a database on the seasonality of fruit production in old-growth forest," Mulkey says. "The data show that the extended El Niño in 1991 was associated with a bumper fruit crop for more than half of the tree species. High wet-season production was repeated during last year's extreme El Niño."

With a $50,000 seed grant from the National Science Foundation and broader canopy research support from the Andrew Mellon Foundation, Mulkey and Wright are raising eight 1,500-watt lamps 40 meters above the forest canopy with the help of a research crane and training them on the leaves in the first attempt to experimentally mimic sunny El Niño conditions.

While some branches will be exposed to increased light for several hours a day during the wet, cloudy La Niña that is now occurring, others will be artificially shaded to see if their fruit production declines. The shading part of the experiment is being conducted by Juan Posada, a UF botany graduate student.

"What we're saying is that the dry season is not necessarily a time of stress for the rainforest trees," Mulkey says. "In fact, it may actually be a window of carbon-gaining opportunity."

Mulkey says the findings could have dramatic implications for reconstructing rainforest habitat destroyed by logging and other human development.

"This should give us a much better idea of what kinds of trees to plant in specific climate regions," he says. "These reconstruction efforts won't work if we don't know which species to use."

Mulkey adds that "knowing how much carbon is likely to be removed or added to the atmosphere by the Earth's vast tropical forests during a given year is critically important for a realistic assessment of global warming."

Cesar Caviedes

Professor and Chair,

Department of Geography,

(352) 392-0494, caviedes@geog.ufl.edu

Jim Jones

Professor, Department of Agricultural

and Biological Engineering,

(352) 392-8694, jwj@agen.ufl.edu

Stephen Mulkey
Associate Professor, Department of Botany
(352) 392-1175, smulkey@ufl.edu

Peter Waylen
Professor, Department of Geography
(352) 392-4652, prwaylen@ufl.edu

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Joseph Kays, Aaron Hoover and Karen Meisenheimer contributed to this article.