CONTACT: John Webster, 505-657-5543, [email protected]
LOS ALAMOS, N.M., Dec. 21, 1998 -- In recent years, the phenomenon called El NiÃ’o has been blamed or, less frequently, praised for all sorts of weather-caused problems and conditions. But despite all the attention, not much is known about its cause.
Data collected at three equatorial Pacific Ocean facilities managed by the Department of Energy's Los Alamos National Laboratory may help researchers understand more about El NiÃ’o, as well as other weather phenomena and the impact of human activities on climate.
The sites are part of DOE's Atmospheric Radiation Measurement (ARM) Program, whose goal is to improve the ability of computer models to predict global climate change. A major thrust of the program is better measurements of solar and terrestrial radiation and cloud processes.
"The most important factors in regulating the amount of solar radiation
reaching the Earth and escaping into space are clouds and water vapor," said Bill Clements, program manager at the Tropical Western Pacific (TWP) Program Office at Los Alamos. "If you can't get those right in the models, then you can't tell about other factors. This makes it difficult to accurately figure out the impact of carbon dioxide and other greenhouse gases."
The DOE established the ARM Program -- the word radiation in the title
refers to solar radiant energy -- in 1989. It is DOE's largest global climate change research effort with participants from eight DOE laboratories, 23 universities, numerous other federal and private laboratories, and eight foreign countries. It is managed from Pacific Northwest National Laboratory.
The program has three major field sites, which are located in widely divergent areas, each with its own type of weather. In addition to the western Pacific, they are located on Alaska's North Slope and in "tornado alley" on the U.S. Southern Great Plains.
Los Alamos is responsible for developing and installing the TWP research facilities, managing the three island sites and delivering the data to the science team. It set up the first facility at Manus Island in Papua New Guinea in 1996. The second was dedicated on Nauru Island on Nov. 20, and a third planned for Kiritimati Island is expected to become operational in 2000.
The three small islands are located within 10 degrees of the equator. Nauru is about 1,350 miles east of Manus, and Kiritimati is another 2,300 miles to the east. This area of the ocean, called the "warm pool" because it consistently has the warmest sea surface temperatures,
pumps heat and moisture into the atmosphere, resulting in the formation of major weather systems.
It is also the home of El NiÃ’o and La NiÃ’a, two components of the Southern Oscillation. During an El NiÃ’o, the warm waters in the Pacific move toward the east, giving rise to changes in weather patterns around the world. When the warm waters move back toward the west, the condition is called La NiÃ’a. Changes between El NiÃ’o and La NiÃ’a occur periodically, but what triggers them is unknown. This cycle is often referred to as the El NiÃ’o -- Southern Oscillation, or ENSO.
"The three sites were chosen to sample east-west gradients in the Pacific," said Tom Ackerman of Penn State University, chief scientist for the TWP Program. "ENSO causes periodic changes in the east-west gradients of ocean and atmospheric conditions. Consequently, we expect to see very different climatic behavior at each of the sites.
"It is very important to characterize atmospheric and oceanic processes with observations over years," Ackerman said. "For example, we want to know how the distribution of cloudiness changes through an entire ENSO cycle. Without this sort of information, it is difficult to formulate, much less test, a comprehensive theory of ENSO."
Stephanie Coonley of the TWP Program Office said long-term data of this type have never been available from the tropical Pacific in the past. "In two years, we already have more data than has ever been collected before," she said.
The study of solar radiation and clouds is crucial in developing models of climate change. The Earth's climate is largely determined by the balance between the solar radiation hitting the planet and the energy re-radiated back into space.
"Clouds can help cool an area or they can help heat it, depending on
the type of cloud," said Clements. "It's very complicated. There's all sorts of feedback mechanisms going on."
To obtain data for use in climate modeling, the three sites contain a wide array of instruments to measure incoming and outgoing solar radiation, the properties of clouds and meteorological information such as temperature, wind speed and direction, and humidity.
The facilities, which are called Atmospheric Radiation and Cloud Stations, or ARCS, also include computers and the necessary communication support systems to deliver data to the scientific team. Housed in modified sea cargo containers, they require minimal maintenance. The ARCS are assembled and tested at Sandia National Laboratories in Albuquerque, N.M.
Data from the tropical Pacific are also collected by satellite, and periodic campaigns of intensive observations are scheduled. The first one is planned for next June at Nauru.
The Pacific sites are being established in close cooperation with local governments, and program officials actively support economic and educational benefits to the islanders.
"We collaborate with the host country at each site," said Fairley Barnes, the deputy program manager at Los Alamos. "We have meetings to find out what the local needs are. At Nauru, we are helping developing a science curriculum for the schools.
"We're also doing things for the communities' infrastructure," Barnes said. "At Manus we upgraded the electrical power grid at the airport, and at Nauru we rebuilt a sea wall."
Los Alamos is operated by the University of California for the U.S. Department of Energy.
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