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Climate: Arctic ice reaches annual minimum

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At its minimum extent in mid-September, Arctic sea ice had left all coastlines — other than northern Greenland and parts of the Canadian Archipelago — free of ice. Map courtesy NSIDC.

Long-term trend still sharply downward

By Summit Voice

FRISCO — The Boulder-based National Snow and Ice Data Center is reporting that Arctic sea ice appears to have reached its minimum extent Sept. 13.

At about 1.97 million square miles, the minimum extent this year was not as extreme as last year’s record low, but still registered as the sixth-lowest on record.

The long-term trend is still a steady decline. Much of the Arctic may be completely free of of sea ice within the next few decades, said NSIDC director Mark Serreze.

“The pattern we’ve seen so far is an overall downward trend in summer ice extent, punctuated by ups and downs due to natural variability in weather patterns and ocean conditions,” Serreze said. Continue reading

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Global warming: Impacts from melting Arctic sea ice could also affect land-based ecosystems

Food web in Arctic biomes could be disrupted

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Caribou are well-adapted to Arctic conditions, but it’s not clear how populations will respond to longer summers and less snow. Photo courtesy USGS.

By Summit Voice

FRISCO — Some of the marine effects of melting Arctic sea ice have already been documented, including changes in the timing of critical algae blooms sustain the ocean food chain.

But land and plant animals living in coastal zones are also likely to feel the impacts, a team of international scientists found after reviewing a big batch of studies on Arctic sea ice loss.

To try and understand those impacts, the scientists examined relationships among algae, plankton, whales, and terrestrial animals such as caribou, arctic foxes, and walrus; as well as the effects of human exploration of previously inaccessible parts of the region. Continue reading

Climate: German researchers document dramatic Arctic ecosystem changes linked with melting sea ice

On a voyage

On a voyage to the central Arctic Ocean, German researchers documented significant changes to marine ecosystems linked with melting Arctic sea ice. Photo courtesy Alfred Wegener Institute.

Massive algae blooms change composition of sea floor food chain

By Summit Voice

SUMMIT COUNTY — Arctic Ocean ecosystems are sure to change in as-yet unexpected ways as sea ice continues to shrink. This summer, German Polar researchers and microbiologists documented one of those changes, observing an unprecedented bloom of ice-loving algae on patches of thin summer ice.

The researchers hypothesized three years ago that ice algae could grow faster under the thinning sea ice of the Central Arctic. This past summer’s observations support the hypothesis: The ice algae were responsible for almost half of the primary production in the Central Arctic Basin. The paper is published in the journal Science.

“We were able to demonstrate for the first time that the warming and the associated physical changes in the Central Arctic cause fast reactions in the entire ecosystem down to the deep sea,” said Lead researcher Dr. Antje Boetius, of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research. Continue reading

Arctic sea ice near record low in January

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January sea ice extent has been dropping about 3 percent per decade, according to the NSIDC.

Northern hemisphere snow cover above average in December and January

By Summit Voice

FRISCO — Arctic sea ice remained well below average during January, about 400,000 miles below the 1979 to 2000 average for the month and the sixth-lowest during the satellite record. The last ten years (2004 to 2013) have seen the ten lowest January extents in the satellite record.

According to the latest update from the National Snow and Ice Data Center, January sea ice extent has been decreasing at abou 3.2 percent per decade. The largest areas of open water were around the Barents Sea and near Svalbard, northeast of Greenland. Sea ice extent was also below average along the east coast of Greenland. Continue reading

Arctic sea ice stayed near record low levels during November

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Arctic sea ice grows fast in November, but the average extent is decreasing from year to year. Graph courtesy NSIDC.

Despite above-average growth, the ice sheet did not catch up to average

By Summit Voice

SUMMIT COUNTY — Even though Arctic sea ice grew at an above-average pace during November, the overall extent still remained one of the lowest on record during the satellite era, reaching 9.9 million square kilometers. Only a couple of other years have seen a lower sea ice extent at the end of November, according to the National Snow and Ice Data Center.

During November, the ice sheet grew at an average rate of 98,600 square kilometers per day. The ice extent remained below the all-time record low for most of November before just matching those record low levels at the end of the month. Continue reading

Climate: Shifting winds drive Antarctic sea ice changes

New study pinpoints regional growth and decline of Antarctic sea ice

Researchers are starting to understand how shifting wind patterns are driving changes in Antarctic sea ice extent. Bob Berwyn photo.

By Bob Berwyn

FRISCO — After compiling more than 5 million individual daily ice motion measurements of sea ice motion around Antarctica, scientists from the U.S. and U.K. say they’re sure that the recent increases in Antarctic sea ice are linked to changing wind patterns in the region.

Essentially, the circumpolar winds are strengthening around Antarctica, said Dr. Ron Kwok, of NASA’s Jet Propulsion Laboratory in California. Why those winds are intensifying, and whether it’s linked with a warming atmosphere remains as a huge question, Kwok said. View a mult-year animation of Antarctic sea ice changes here.

“We are basically finding evidence of change over a long time scale … That’s why it’s inportant to quantify the mechanisms,” he said. “It’s probably associated with a changing climate. The Antarctic sea ice interacts with the global climate system very differently than that of the Arctic, and these results highlight the sensitivity of the Antarctic ice coverage to changes in the strength of the winds around the continent.” Continue reading

Climate: Ice-free Arctic ahead?

A warming Arctic is changing the configuration of the jet stream, which affects mid-latitude weather. GRAPHIC COURTESY NOAA.

Researchers cautious about predicting the demise of Arctic ice

By Bob Berwyn

SUMMIT COUNTY — Despite a steady trend of melting Arctic sea ice, experts with the National Oceanic and Atmospheric Administration aren’t yet willing to make any predictions as to when the region will be completely ice-free during the summers.

The National Snow and Ice Data Center earlier this week said that the melt bottomed out in mid-September at new record low extent, but lingering thick, multi-year ice along the north coast of Greenland may persist for decades to come, preventing a total melt-out, said  NSIDC ice researcher Walt Meier, speaking during a Sept. 20 teleconference.

That may lead to a plateau at some during what’s been somewhat sensationally described as the Arctic ice death spiral, Meier said, adding that conditions are so variable from year to year that it’s hard to predict the timing. Continue reading

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