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In a paper to be published Friday, June 3, in the journal Science, researchers report that 125 lakes categorized as large because they were more than 40 hectares (nearly 100 acres) completely disappeared and are now re-vegetated and considered permanently drained. More than 1,000 other large lakes shrank to a smaller size.

"It's quite significant," said Yongwei Sheng, a SUNY College of Environmental Science and Forestry (ESF) faculty member who did remote sensing work on the project. "This is the result of warming and changes in the permafrost. We believe it's due to global climate change."

Previous studies have shown that Arctic warming has accelerated since the 1980s.

Sheng said the lake data raise questions about how altered ecosystems will affect animal habitat, especially for migrating birds that depend on the lakes for water.

Sheng said the lakes drained, some partially and some completely, because of changes in the permafrost, subsoil which remains frozen throughout the year. "It's getting warmer there, so some of this material is melting and the lakes are draining," he said.

The study focused on 624,000 square kilometers (more than 150 million acres). Sheng said researchers have never before studied the extent of lake changes in such a large section of an Arctic region.

Sheng, now an assistant professor in the Faculty of Environmental Resources and Forest Engineering at SUNY-ESF in Syracuse, N.Y., worked on the project with Larry C. Smith at UCLA. Smith is a co-author of the paper, along with Glen MacDonald of UCLA and Larry D. Hinzman of the Water and Environmental Research Center at the University of Alaska in Fairbanks.

Satellite images revealed the change in land surface. Sheng compared images obtained in 1973 by the first land resources satellite used to gather information about geographical formations with images collected in 1997 and 1998. By comparing the two generations of satellite images, the researchers determined the changes in the lakes.