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Scientists plumb
the oceans for
climate clues

By Helen Altonn
Star-Bulletin

About 3,000 devices will be floating in the world's oceans within five years -- reporting temperature, salinity and other data to satellites in a project dubbed ARGO.

This is one of a number of international efforts being discussed here this week by researchers concerned with understanding and predicting climate changes.

They are members of the scientific steering group of Climate Variability and Predictability Project, part of the World Climate Research Programme.

The University of Hawaii's International Pacific Research Center, a climate research center established in 1997 by the United States and Japan, is hosting the weeklong meeting.

Scientists are reviewing progress and planning future work to improve understanding and predictions of El Ninos, monsoons and other climate changes.

Russ Davis, who developed the technology for the drifting floats at the Scripps Institution of Oceanography, La Jolla, Calif., is among 58 scientists attending the sessions at the East-West Center.

Thus far, about 1,400 floats are circulating in the oceans, Davis said, noting other countries have developed their own versions of the instrument.

They are programmed to drift at a depth of about 6,600 feet, measuring temperature and salinity and rising to the surface every couple of weeks to transmit data to satellites.

"The main thing is they're telling us what's below the surface to 2,000 meters," Davis said.

The data will enable researchers to identify changes in the ocean much more rapidly, particularly bigger variations from year to year and decade to decade, he said.

The floats also are operating in parts of the world such as in the South Pacific, where ships don't go and it's hard to get observations, Davis said. They can be dropped by aircraft or ship and they have a lifetime of five or more years, he said.

Davis said the original floats had microprocessors with a schedule of operations but they couldn't receive information from the researchers.

Scientists can talk to them now via satellites and make changes, such as in the sampling frequency, he said.

John Gould, director of the International CLIVAR Project Office in Southampton, England, said the project's purpose is to investigate how the atmosphere, ocean, land and ice masses are responding to natural processes and to mankind's activities.

Researchers are addressing issues of immediate relevance to populations, Gould emphasized.

For example, Juergen Willebrand of the Institute for Meteorology in Kiel, Germany, pointed out that better understanding of the ocean-atmosphere led to routine predictions of the most recent El Nino in some regions.

Still, improvements are needed to increase accuracy, said Willebrand, co-chairman of the CLIVAR Scientific Steering Group with Tony Busalacchi, with NASA's Goddard Space Flight Center in Greenbelt, Md.

"El Nino is an example, a microcosm, of what CLIVAR is about," said Busalacchi, listing some of the flaws in predicting the phenomenon.

He said more research is needed to understand ocean-atmosphere linkages and to improve climate forecasts in areas other than the tropics.

One of the international program's major goals is to understand and predict the effects of greenhouse gases and aerosols on the climate system.

The scientists are looking to the past to gain a better understanding of the future. They're trying to reconstruct climate variations over the past 2,000 years from coral, ice-core and tree-ring records.

"We must make it clear that CLIVAR research directly affects people's lives and is worth billions of dollars (in economic consequences)," he said. "We deal with things in the news every day, yet CLIVAR is not mentioned."