The ponderous churning of the North Atlantic Ocean that carries warm water northward and returns deep, cold water to the south appears to have slowed in the past decade or two. That would mean that this oceanic radiator is bringing less heat to warm Europe and, if global wanning is behind the slowdown, will carry less and less heat to high latitudes in the future. But the slowing is hardly larger than the uncertainty of the observations. And "we don't know enough about the ocean to know whether this represents a trend" that will persist, says physical oceanographer Harry Bryden of the National Oceanography Centre (NOC) in Southampton, U.K. Bryden and NOC colleagues report detection of the slowdown this week in Nature.
展开▼
