Nature News

Antarctica’s deep ocean waters are getting colder after years of warming, say researchers who have just returned from a Southern Ocean voyage aboard the German research vessel Polarstern.

Samples from previous expeditions showed that water at a depth of 4,500 metres in the Weddell Sea warmed by a tenth of a degree Celsius between 1989 and 2005, although the warming trend may have begun earlier. The latest work, by researchers from the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, found that temperatures have cooled slightly since 2005, suggesting that more cold surface water is reaching the deep ocean, perhaps as a result of changes in sea-ice coverage and atmospheric conditions. The team plans to revisit the region during the summer of 2010–11. See story here.

Alfred Wegener for Polar and Marine Research