Ice-Free Northeast Passage Allows First Commercial Voyage Ever without Icebreakers
08.09.2009 - Atmosphere & Space, Water & Oceans, Ice & Snow, Human Dimension, Other, Arctic
For the fourth time in only five years, the Northeast Passage has opened, cutting 4,500 miles off the 12,500-mile trip from the European Atlantic to the Asian Pacific for shipping companies. Two German ships recently were able to make the first commercial voyage ever through the Northeast Passage without the assistance of icebreakers.
Mariners have been trying to sail the Northeast Passage since1553. Until 2005, when record-breaking ice melt opened the passage to ice-free navigation, ice breakers were always needed on any journey.
The opening of the waterway is the consequence of yet another summer of significant warming which brought August ice extent to about 19% below the 1979-2000 average, the third lowest sea ice extent behind 2008 and 2007. Although there has been two straight years without a new record sea ice melt, this does not mean the Arctic sea ice is recovering; the reduced melting in 2009 compared to the two previous years was the result of a different atmospheric circulation pattern this summer that created winds that pushed ice towards the Siberian coast and discouraged export of ice out of the Arctic Ocean.
Results of a study published in the American Association for the Advancement of Science (AAAS) show that the last time the Northeast Passage was ice-free was about 5,000 to 7,000 years ago, when the Earth's natural orbital variation allowed more sunlight to reach the Arctic than today. A new technique that examines organic compounds in Arctic sediments left behind by diatoms living in sea ice gives hope that a detailed record of sea ice extent going back to the end of the last Ice Age 12,000 years ago hopes to give a more precise figure.
Meanwhile, the Northwest Passage, which opened up again in 2007, remained closed this summer due to an atmospheric pattern that created winds which pushed old, thick ice into the channels of the Northwest Passage. According to research Stephen Howell at the University of Waterloo (Canada), the opening of the Northwest Passage was more a consequence of multi-year ice being driven into the channels than of increased melt.
