Features

The Associated Press 

With the impact of the oceans on weather and climate becoming increasingly apparent, scientists are launching an ambitious worldwide effort to test the waters. 

They are planning to launch some 3,000 observation buoys to measure the temperature and salinity of the oceans that cover nearly three-quarters of the planet’s surface. 

The United States’ participation in the international effort, known as Argo, was announced Tuesday by Commerce Secretary Norman Y. Mineta. 

“We are taking the plunge to understand our oceans,” he said. “What happens in the deep oceans is a big part of where the weather patterns begin.” 

Sample buoys have already been deployed and a ship was setting sail from San Diego on Tuesday to launch six more, said D. James Baker, head of the National Oceanic and Atmospheric Administration. 

The buoys will enable scientists to study further the impact of the oceans. Some of these effects are known already. 

It’s the change in the surface temperatures in the Pacific Ocean that drives the El Nino and La Nina phenomena that have affected weather around the world – sometimes in spectacular and disastrous ways. 

It’s the warm tropical waters that provide moisture and energy to generate the great storms known as hurricanes and typhoons. 

And it’s the Atlantic Ocean’s mild Gulf Stream that keeps the climate of Europe warm and pleasant, compared to other regions at the same latitude. 

The Argo probes will test the waters where only occasional surface ship measurements have been available before. 

The buoys initially will be distributed about 185 miles apart and when deployed they will sink to a level 2,000 meters – just over a mile – deep where they will drift for 10 days. 

The buoys will then surface, measuring the temperature and salinity of the layers of water they pass through. Once on the surface, they will radio their position and data to a satellite and sink again for another 10-day drift. 

The data collected will be retrieved from the satellites and made available freely to all interested scientists for use in computers that help forecast the weather and to better understand how the oceans operate. 

The deep-water measurements will provide vertical profiles of water conditions similar to the atmospheric measurements currently collected by balloons. 

The movement of the probes a mile below the surface will help chart deep currents in the oceans. The temperature profiles will give scientists information on the energy contained in the waters and the salinity helps them understand its density. 

For example, the giant Gulf Stream moves warm tropical water northeastward across the Atlantic, moderating the climate of Europe before cooling and sinking for a return trip south deep in the oceans. 

Some scientists fear that global warming could melt the Arctic ice cap, sending masses of fresh water into the North Atlantic. If that happened, it would reduce the ocean’s salinity and thus its density. That could prevent the Gulf Stream from sinking, possibly changing the overall current and in the process, Europe’s climate. 

Over time, these probes will help scientists collect data to see if such changes are taking place. 

The probes, costing an estimated $12,000 apiece, are expected to last four or five years. Deployment of the probes is expected to reach 700 per year by 2002 and eventually total 3,000. 

The United States has committed to supply 1,147 floats. 

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On the Net: 

Argo site: http://www.argo.ucsd.edu 

National Oceanic and Atmospheric Administration: http://www.noaa.gov