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Next: 'La Nina' May Make Wet Areas Wetter, Dry Areas Drier

By Elizabeth OlsonSpecial to The Christian Science Monitor / April 8, 1998



GENEVA

Move over El Nino. In a few months, the "boy child" weather phenomenon's little sister, dubbed "La Nina," is likely to be dominating the climate news.

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Unlike El Nino, which reverses normal weather patterns, La Nina "tends to accentuate the normal pattern," says Dr. Michael Coughlan, director of the World Climate Program. The program is part of the Geneva-based World Meteorological Organization (WMO), the United Nations weather-monitoring agency set up in 1951.

"La Nina means that wet areas become wetter and dry areas drier. La Nina tends not be as severe or marked as El Nino, but it does enhance the normal pattern," he says.

La Nina could bring abnormally cold conditions to the eastern Pacific regions, which are normally dry. This area includes the California coast, which has been buffeted recently by El Nino-driven floods and landslides.

Like El Nino, La Nina is a series of processes in the ocean that affect the atmosphere. El Nino stems from a warm Pacific current off South America. La Nina is characterized by unusually cold ocean temperatures in the same area.

Views that a La Nina will follow hard on the heels of the current El Nino are not unanimous. While some computer models predict the "cold weather event" could begin sometime between July and September of this year, others models predict a return to normal weather. Ants Leetsmaa, director of the Climate Prediction Center at the US National Oceanic and Atmospheric Administration in Maryland, says the global climate is likely to experience a "soft landing" after El Nino ends sometime this summer.

The two weather patterns have been identified in the past 30 years and are considered a "coupled phenomenon" that at first only piqued the curiosity of researchers.

As part of a global effort, the World Climate Program began scientific measurements, including measuring ocean currents, which began to lead less than two decades ago to unraveling the climate mystery. The severe El Nino episode of 1982-83, which scientists consider a "wake up" call, stimulated research efforts.

The most recent, more extreme El Nino, which brought heavy rain to some parts of the world and drought to others, is believed to have peaked. But Dr. Coughlan says its impact will continue at least until midsummer. He warns, however, "Our models to predict these events are still rudimentary."

Global alert system set up

The need to translate scientific observations about climate into something practical and usable caused the World Climate Program to set up the Climate Information and Prediction Services (CLIPS) in 1995.

Its mission is to tie together the information on weather gathered worldwide by the national meteorological services. Of the 185 WMO member countries, many have such national services, which feed local conditions into WMO's global network.

Any industry that is sensitive to climate and seasonable variations - from agriculture to tourism - can benefit from climate predictions. For example, a farmer who is facing a wetter-than-normal growing cycle could choose to plant a different crop. Or a rancher might decide to limit the number of animals raised in order to avoid foot rot.

Other practical applications include clearing storm drains, as was done in Peru. It didn't stop flooding, but helped lessen the danger by assuring that excess water had an unobstructed place to flow, according to the WMO.

Australia was prepared

In Australia, the 1982-83 El Nino produced severe bush fires which destroyed thousands of homes and claimed many lives in the eastern and southeastern parts of the country. WMO research shows there were a larger number of fires during the recent El Nino, but less damage and loss of life because firefighters were better prepared. They had more firefighting equipment and materials on hand, and took more precautions, such as digging additional fire breaks.

For now, there is no worldwide climate safety net, the WMO admits. "We're not used to seasonal predictions, and how to use them," says Coughlan. "We're in a little bit of a learning phase," he adds. "We have to learn how to present predictions in a way that they can be used in a practical sense, to benefit not only farmers, but those who control areas like water resources, or someone in the health field where climate can affect diseases."

Down the road, the WMO hopes its CLIPS project will produce practical, down-to-earth ways to make wise use of climate forecasts. In the meantime, while weather is still the cornerstone activity of the organization, it is getting used to the new world of climate prediction.

"WMO has always been weather central, but climate touches a much broader area but with a slower time scale. It's not just a matter of saying whether you should take an umbrella or not today. It's longer range, bigger decisions that are involved, and ones that have a lot more economic consequences," Coughlan says.