Courtesy of the Japanese Marine Science and Technology Center.
An Argo float is deployed by the Japanese Coast Guard
Scientists studying Earth's global climate quickly hit an information gap: There are few weather stations and instrumented ships on the oceans that cover three-quarters of our planet. “The ocean has been badly sampled—most of the existing measurements are from the Northern Hemisphere,” says oceanographer Dean Roemmich of the University of California at San Diego. He is rectifying the situation by heading the Argo project, a $20-million-per-year program that is deploying 3,000 submarine-shaped instrumented floats around the world. The floats—870 released so far—sink and surface on a 10-day cycle, measuring temperature and salinity through the top mile of ocean water. When completed in 2006, the network will allow researchers to monitor our planet as never before. “Argo should help us think about the ocean as a unified climate system,” Roemmich says.
Meanwhile, Curtis Ebbesmeyer, an oceanographer in Seattle, is keeping tabs on large-scale ocean currents using a simpler technique. He follows items lost from ships during storms. In his latest venture, he is trailing 29,000 rubber ducks and other bath-time animals that spilled off a freight ship into the Pacific in 1992, relying on reports from beachcombers who find the toys as they wash ashore. Ebbesmeyer and Jim Ingraham of the National Oceanic and Atmospheric Administration analyze the sightings with a computer model to reconstruct the currents that brought them to land. “There's so little known about the ocean that we need to look at every scrap of evidence we have,” Ebbesmeyer says.