SAN DIEGO — The procession of rainstorms and high surf that have hit the California coast for the last month is a sign that El Nino--the unusually warm ocean current that caused worldwide havoc three years ago--is back, a well-known San Diego research meteorologist said Thursday.
That conclusion by Dr. Jerome Namias, head of the Climate Research Group at Scripps Institution of Oceanography, was seconded by a weather research team at Columbia University and officials at the National Oceanic and Atmospheric Administration, who said all indications are that a new El Nino, if not already here, is certainly developing.
But unlike the "granddaddy" El Nino of 1982-83, which seriously disrupted weather patterns across three-fourths of the globe, causing more than 800 deaths and $8 billion in damage, the new El Nino is expected to be significantly less severe, according to Namias and the other scientists.
That observation is based on early physical evidence, however, and no one can say with certainty how intense another El Nino may become. "Right now, it doesn't look like it will be of the intensity that we had with that granddaddy (in 1982-83) . . . but I could be wrong," said Namias, whose weather predictions aided the Allied invasion of North Africa in World War II and who last November forecast heavy winter rainfall this year for most of California and the West.
The effects of the new El Nino are expected to be felt more in parts of South America, particularly Ecuador and Peru, where heavier than normal rainfall is predicted, and in Australia, Indonesia and the western Pacific, which are expected to be drier than usual, the scientists said. It is also likely that parts of the southeastern United States will be somewhat cooler and wetter next winter, while Alaska, the northwestern United States and parts of Canada will be warmer.
"Now when you get to California, it's more interesting," said Stephen Zebiak, associate research scientist at the Lamont-Doherty Geological Observatory at Columbia University. Zebiak, along with his colleague, Mark Cane, has developed a computer model that forecasts an El Nino this year.
"It (California) can go to one extreme or the other," Zebiak said in a telephone interview. "It can be very dry or very wet or stormy. But it should be emphasized that whatever way it goes, none of these things may be particularly pronounced."
Both Zebiak and Namias noted that while the last El Nino staggered California with torrential rains, flooding, mud slides and destructive tides, a less severe El Nino occurred during 1976-77, when California was in the grip of a drought.
Occurs With Regularity
El Nino, Spanish for "The Child," is characterized by unusual warming of the eastern tropical Pacific. It happens with some regularity, usually every six to seven years, though there have been occurences at more frequent intervals. An El Nino usually lasts 18 months to two years.
In 1982-83, the ferocity of El Nino took everyone, including scientists, by surprise. Perennial winds and currents died or reversed direction. Normal sea levels and temperatures soared and plummeted. Fish and sea birds by the millions disappeared. Some areas of Peru, which normally receive six inches of rain, got 12 feet.
In French Polynesia, the first typhoon in 75 years was recorded. Australia suffered through its worst drought in 200 years and China had floods in the south and drought in the north.
While the scientists agree that an El Nino is either already here or on its way, their reasons for the observation differ.
Namias says the atmospheric wind system that has brought California the high frequency of rainstorms and high surf in recent weeks, coupled with slightly warmer water temperatures off the coast, are indicators that another El Nino is here.
'Evidence Is Considerable'
"The winds are coming out of the lower latitudes from Japan, going north of Hawaii and straight to here," Namias said. "These are signs of an El Nino. . . . I think the evidence is considerable in this case."
Namias says he's from a school of thought that believes changes in weather and wind patterns cause El Nino, while some of his colleagues believe it works the other way around; that it's El Nino that produces changes in weather.
The El Nino forecast by Zebiak and Cane is based on a computer model that analyzes surface water temperature in the Pacific Ocean on a line with the Equator from near South America to east of Hawaii. The model simulates conditions in the atmosphere and the ocean and then uses wind data to forecast ocean surface temperatures for several months.
"Our model is based on what happens in the ocean and atmosphere and not statistics," Zebiak said. "What the model is saying undisputedly is that an (El Nino) event will happen later this year. There's considerable evidence in the past few weeks that an event is already under way."