Tue Jan 4th, 2011 at 02:20:54 PM EST
Remember this diary on climate change and Europe's recent cold winters? Now from France Presse we have this article:
Scientists have found evidence of a "drastic" shift since the 1970s in north Atlantic Ocean currents that usually influence weather in the northern hemisphere, Swiss researchers said on Tuesday.
The team of biochemists and oceanographers from Switzerland, Canada and the United States detected changes in deep sea Atlantic corals that indicated the declining influence of the cold northern Labrador Current.
They said in the US National Academy of Science journal PNAS that the change "since the early 1970s is largely unique in the context of the last approximately 1,800 years," and raised the prospect of a direct link with global warming.
The Labrador Current interacts with the warmer Gulf Stream from the south.
They in turn have a complex interaction with a climate pattern, the North Atlantic Oscillation, which has a dominant impact on weather in Europe and North America.
Scientists have pointed to a disruption or shifts in the oscillation as an explanation for moist or harsh winters in Europe, or severe summer droughts such as in Russia, in recent years.
"Now the southern current has taken over, it's really a drastic change," Schubert told AFP, pointing to the evidence of the shift towards warmer water in the northwest Atlantic.
Crudely put, the cold Labrador Current, which had been responsible for New England's traditional cold winters, is shutting down, allowing the Gulf stream to pool up in the northwest Atlantic instead of carrying warm water over to Europe where it "belongs". This in turn is creating milder winters in New England and more extreme weather in Europe.
It is not the Gulf Stream that is shutting down--it is the Labrador Current. However, the effect is indeed what we have been noticing by looking out our windows, without the benefit of climate science.