Dolphin-sized robots are giving clues to a thaw of Antarctica's ice in a sign of how technology is revolutionizing data collection in remote polar regions, scientists said Monday. An international study led by the California Institute of Technology used three yellow "gliders," about 6 feet, 6 inches (2 meters) long and each costing $240,000, to measure temperature and salinity in the depths of the Weddell Sea off Antarctica. The measurements showed how vast eddies drive heat into shallower waters, helping thaw coastal ice. The findings, in the journal Nature Geoscience, back up theories about how heat moves south.
One of the three gliders got lost, but Karen Heywood, a co-author of the study at England's University of East Anglia, said the technology still was cheaper than a 2007 trip that required a ship costing $30,000 a day, with many stops, to collect less data. Robot gliders can be left for months, diving and surfacing with tiny adjustments to buoyancy. About 3,600 free-drifting "Argo floats" have been deployed worldwide since 2000 to help monitor temperatures and salinity in the seas.

IN-DEPTH
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