Arctic sea ice once again shows considerable melting
This September, the extent of Arctic sea ice shrank to roughly 4.7 million square kilometers, as was determined by researchers at the Alfred Wegener Institute, the University of Bremen and Universität Hamburg.
Though slightly larger than last year, the minimum sea ice extent 2017 is average for the past ten years and far below the numbers from 1979 to 2006. The Northeast Passage was traversable for ships without the need for icebreakers, according to phys.org.
The sea ice in the Arctic is considered a critical element in climate processes, and a valuable early-warning system for global warming.
Accordingly, the September minimum extent is an important indicator of climate change. Despite an especially warm winter, the current extent of sea ice does not represent a new record low; nevertheless, the amount of ice loss is massive.
As sea-ice physicist Marcel Nicolaus from the Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI) explains, “This year’s sea ice extent is again on a very low level: The observed September value of the past eleven years has consistently been lower than in any of the previous years.”
This winter, the Arctic remained unusually warm, and the sea-ice coverage in March was lower than in any March before.
Lars Kaleschke from Universität Hamburg’s Center for Earth System Research and Sustainability stressed, “Thanks to the relatively cold summer, the sea ice managed to bounce back somewhat, but this year’s September minimum is by no means a good sign.
“Though the amount of sea ice is of course subject to natural fluctuations, the long-term decline is obvious.
“For comparison, the summertime minimums in the 1970s and 1980s were roughly seven million square kilometers.”
The sea-ice covered area is measured with the help of satellites. The high-resolution microwave satellite data are jointly provided by the University of Bremen and Universität Hamburg. They allow to precisely analyze the daily sea-ice extent over the entire Arctic. That’s particularly important for the shipping industry.
Gunnar Spreen from the University of Bremen’s Institute of Environmental Physics said, this summer, the Northeast Passage along the Russian coast could be used without the need for icebreakers, and many ships also used the Northwest Passage.