The cold water beneath the winter pack ice in Baffin Bay is getting warmer, according to measurements taken by thermometer-wearing narwhals. The data collected from the diving mammals fill in a geographical and seasonal gap in the region’s climate records, as no winter temperatures were previously available from the area. The data also confirm that a warming trend measured during earlier summer-only studies of the West Greenland Current continued in the three years to 2007.

“We basically knew nothing about winters up in Baffin Bay,” says physical oceanographer Mike Steele at the University of Washington in Seattle, who co-authored the study, which appeared last week in the Journal of Geophysical Research. “But there is a lot of interest in the flow of seawater around Greenland.”

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