Can malaria be predicted by changes in ocean temperatures? Can you foretell a dengue fever epidemic by reading atmospheric pressures? Does hantavirus disease follow El Niño? Are climatologists the doctors of the future?

The answer is yes. At least climatologist Nicholas Graham at Scripps Institution of Oceanography in La Jolla thinks so. If you can predict El Niño, Graham believes, you can predict where and when malaria will strike, where droughts will hit, where cholera can float to. You can save lives.

Since this latest El Niño began, Graham has become the world's tour guide to climate change. He's taken the phrase "applied science" to a new level. Will cows on the Serengeti plains have grass to eat in 1999? Ask Nick. Will the tsetse fly spread south of the Tropic of Cancer this year? Ask Nick. Ask him if cholera will become epidemic in Bangladesh in the next monsoon. If there will even be a monsoon next season.

Lots of world leaders ask Nick. The Scripps climatologist regularly consults with heads of state. Last week he was prophesying in Brazil, where half the country has been inundated with rains and the other half has endured drought conditions. This week, for the fourth time in a year, he's in East Africa, which is also suffering from El Niño-driven flooding.

El Niño, Graham says, is key to just about everything. It's because of El Niño that he has this job, that the National Oceanic and Atmospheric Administration (NOAA) decided to team up with Columbia University's Lamont-Doherty Earth Observatory and Scripps Institution of Oceanography to form the International Research Institute for Climate Prediction.

"We were all jerked into action by the 1982-1983 El Niño," says Graham. "It had devastating consequences around the world. There was a big effort to understand El Niño -- the warming of the tropical Pacific -- and its impact on the climate elsewhere. And to try to predict it next time."

They predicted this one fine.

The El Niño effect refers to a pool of warm water, twice as large as the U.S., that usually surrounds Indonesia on the far-western rim of the Pacific. It is normally kept in place there by the pressure of tradewinds blowing westward from the Americas. When those tradewinds fail, the whole pool drifts eastward, not stopping till it collides with Peru. But its influence is felt as far away as Africa. El Niño has been called the most influential worldwide natural event after the four seasons. It profoundly influences just about everything, from droughts in Australia to hantavirus dangers in California.

When he's not on the road, Nick Graham watches it all from his desktop screen in La Jolla, checking six or seven computer "models" -- projections of climate predictions -- from around the academic world. He clicks on his keyboard and great flumes of red gush out across his computer screen. They are satellite views of El Niño straddling the Pacific, like a rocket exhaust tail spewing out of Peru. Each of the models uses data from satellites, water-temperature statistics, and other input to predict what's going to happen next.

The stated goal of the research institute, Graham says, is to make "the best possible climate predictions and distribute the information in useful format especially rapidly for interested parties such as public health authorities and fishery people."

"This is the big test year," says Simon Mason, one of Graham's two assistants. Mason says El Niño is the perfect "test bed" because it covers a specific area of natural "global warming"-- the Pacific. El Niño acts as a model to work out the kinks in the quest to predict all weather and global warming on a worldwide basis.

Graham and his colleagues have teamed up with public- health experts to predict disease epidemics that El Niño may encourage. Warmer temperatures and increased rainfall to our region, he says, spread water and insect-borne diseases such as malaria, its cousin dengue fever, cholera, and hantavirus. Some researchers even believe that a current outbreak of cholera as far away as the horn of Africa is linked to El Niño.

Graham has been studying the spread of malaria -- which afflicts more than 300 million people a year around the world -- in Colombia. "There," he says, "you can see a very clear relationship between El Niño occurrences and malaria outbreaks. When there's an El Niño, there tends to be a lot of malaria. Also dengue fever."

He and a Colombian scientist have been studying cases of malaria reported there since 1960. The years with the most cases almost all coincide with the presence of El Niño. Ironically, Colombia, though warmer, is drier during an El Niño. "That means more stagnant puddles for mosquitoes to breed in," explains Graham. Graham reported to the American Geophysical Union in December that his models predicted increased temperatures for Colombia in 1998. More modeling showed that as the weather warms, mosquitoes and other insects will increase their range into higher elevations that were previously malaria-free. "It is temperature occurrences associated with El Niño that affect their life cycle," says Graham, "how often they eat, how fast the protozoa that spreads malaria takes to develop inside the mosquito depend on temperature fluctuations and contribute to the increase in malaria cases there."

At least, he notes, he has been able to warn the Colombians in time to stock up on appropriate medicines.

But not all countries react the same to El Niño: another study published in December suggests that in Venezuela, it is the year after an El Niño that the number of malaria cases shoots up by a third.

Graham believes the main element governing these outbreaks is the ocean temperatures. The warm waters are here off the Americas, but their effects can be far-ranging. "In Central East Africa, where they had tremendous flooding this year," says Graham, "they've got huge disease problems now. The flooding was induced by El Niño. Now [with unseasonal rains] in normally dry areas they have lots and lots of standing water. Then you get not just the vector-borne diseases [like malaria] but the ones spawned in overwhelmed sewage systems [that] flood into the public water supply."

The very air swirled about by El Niño might also help point to the onset of dangerous diseases, according to New Zealander Dr. Simon Hales. Hales is working with NOAA to see if dengue fever epidemics can be forecast from data on differences in atmospheric pressure.

Perhaps most worrisome for Californians and others living near the unseasonably warm waters of the Eastern Pacific: warmer ocean temperatures can allow phyto-plankton, which carry the cholera bacteria, to grow faster and spread. Some scientists blame El Niño and cholera-bearing plankton for the 1991 cholera outbreak in Peru. The idea of ocean-spread diseases is alarming, but according to Rita Colwell, a Maryland-based cholera expert working with Graham, it would be extremely unlikely to be a threat here even if the cholera-bearing plankton was brought as far north as San Diego by warm El Niño waters.

"The numbers you'd have to swallow would be a million of the bacteria in half a teaspoon of water. You wouldn't have those numbers. And when the populations of the plankton do gather in sufficient numbers, they make the water turbid, eutrophic, muddy brown. You probably wouldn't want to swim anyway."

Colwell is excited by Graham's computer-based powers of prophecy. "It's critical that we understand ecology globally. Influenza's spread in winter is related to the environment. Diarrhea is a summer disease, [but the] campylobacteria [linked to it], transmitted by chickens, peaks in the spring months. There is a climatological and environmental component to infectious disease, and we need to quantify it, and we need to do it quickly."

El Niño, Colwell thinks, is a great opportunity. "The El Niño is like an experiment. Mother Nature has warmed up and changed the climate in a very specific way for us, so we're able to collect the data. It's time we developed a global ecological system that includes oceanography, microbiology, meteorology, space science, medicine, and public health. To bring all of these areas together in sharp focus -- it's just exquisitely exciting. A watershed moment."

Colwell thinks San Diego's biggest concerns in El Niño years are insect-borne viruses like the hantavirus. The population of deer mice, which carry it, explodes in warm, wet El Niño weather. If a dry period follows, food becomes scarce for the swollen mice population. Thousands can be driven into homes in search of food.

Graham is just as fascinated with El Niño's causes as its effects. "The ocean, being heavy and big, has a very long memory -- up to 50 years. The atmosphere has a very short memory, weeks. So the atmosphere is sort of slave to the ocean temperatures. It does what the ocean temperatures tell it to do. But then the winds blow, and the wind causes the ocean temperature patterns to change. So the whole thing goes through a dance. A coupled evolution."

Graham's own prediction model (which he developed with colleagues Tim Barnett and Mojib Latif) is called a "hybrid."

"It's got a dynamical, fairly complex ocean model [based on inputs from satellites, buoys planted across the Pacific, and analyses of fish migration and currents], but it's coupled with an atmospheric model that uses only statistics."

So Graham also considers results from other climate-prediction models. "There are six or seven primary El Niño prediction models produced around the world," says Juli Trtanj of NOAA's office of global programs. "Each has different strengths and weaknesses given different climate conditions. So Nick, apart from producing his own model, looks at all the climate models and as much climate information as we have, then produces a 'net assessment.' "

Trtanj says this single voice of prediction has been invaluable. "It's the first time that that information has ever existed. If you want to know the physical impact of El Niño in terms of rainfall and temperature, Nick's got the only comprehensive look. [Developing] the ability to forecast El Niño, period, in these last six or seven years is a phenomenal achievement for the climate-science community. They're very excited."

The last great element you have to remember, says Graham, is the "anthroprogenic" factor. Stuff caused by man. Pollution. Global warming. Carbon dioxide gases. But his hybrid model can't cope with that, and with only a million-dollar annual budget to run his show, he probably won't be getting any new toys soon, despite predictions that El Niños will become more frequent.

Nonetheless, Graham, who's been working at Scripps since 1987, is glad to be at the center as climatology takes on a pivotal role. "The ideal person to study climate in the future will have knowledge in public health, agriculture, water resources, fisheries -- that kind of knowledge will be key to being able to use climate predictions," he says. "In the '90s this job is all about taking the science out of the laboratory and applying it to the real world."

Graham won't know till around June how successful he has been in his role as an updated Farmer's Almanac. But one thing he's certain of.

"This El Niño has just peaked," he says.

That's good enough for Juli Trtanj, "If Nick says it has peaked," she says, "it has peaked."