Australian scientists document early start to melt season
Australian scientists say Antarctic sea ice started its annual spring retreat early this year and has set new daily record lows for extent during late September — during the Austral spring, when Antarctic sea ice is at a maximum.
In a press release, the Antarctic Climate & Ecosystems Cooperative Research Centre said the sea ice extent started its annual retreat early, just two years after winter sea ice extent around Antarctica reached a new record high in September 2014, when it exceeded 20 million square kilometres for the first time since satellite measurements began in 1979.
This year, Antarctic sea ice began its annual spring retreat about four weeks earlier than average, after peaking at 18.5 million square kilometres on 28 August 2016, which was close to the lowest winter maximum on record.
Arctic warming twice as fast as rest of the planet
FRISCO — Parts of the Arctic Ocean are warming by nearly 1 degree Fahrenheit every decade, and overall, Arctic temperatures are rising twice as fast the global average, climate scientists said today as they released results of an annual Arctic Report Card.
The report documents increasing air and sea surface temperatures, declining reflectivity at the surface of the Greenland ice sheet, which reached a new record low last summer. And there is ongoing shrinkage of spring snow cover on land and summer ice on the ocean.
Melting sea ice likely a factor in population decline
FRISCO — With a 2017 endangered species listing deadline looming, federal researchers are trying to pinpoint Pacific walrus population numbers. In the newest study, the U.S. Geological Survey said the population dropped by about half between 1981 and 1999, but scientists aren’t sure if the numbers have stabilized since then.
in 2011, the U.S. Fish and Wildlife Service acknowledged that the species was under pressure from sea ice loss and over-harvesting, but didn’t formally add the Pacific walrus to the endangered species list. A federal court said the agency must make a final determination by 2017. Continue reading “Study tracks big drop in Pacific walrus numbers”→
Global warming likely to reverse trend in coming decades
By Summit Voice
FRISCO — Climate scientists have long suspected that increasing winds around Antarctica have been the main cause of growing sea ice extent in the southern hemisphere, and new research from the University of Washington shows how and why that might be happening — even as overall global temperatures warm.
Global warming deniers have tried to use the growth of Antarctic sea as a weapon in their battle against science, but climate researchers point out that the loss of Arctic sea ice far outweighs the small increase in the southern hemisphere. And the new research suggests that, as global temperatures continue to increase, Antarctic sea ice is all but certain to start shrinking.
Overall, Antarctic sea ice has been increasing by about 1 percent annually, which has led to record sea ice extent in the region the past few years. As of September 16, Antarctic sea ice extent reached about 7.51 million square miles, a record for the date and about 3.9 percent above the 30 year average. By contrast, this year’s Arctic summer minimum ice extent is approximately 30 percent below the 30-year average. Continue reading “Climate: Winds driving Antarctic sea ice growth”→
Study shows fundamental ecosystem changes under way
By Summit Voice
Sea ice decline is already changing some Arctic ecosystems in fundamental ways, according to University of Alaska Fairbanks scientists. As part of review team, the two researchers showed, for example, that disappearing sea ice leads to a loss of sea-ice algae, at the very base of the Arctic marine food web. Larger plankton is thriving, replacing smaller, but more nutrient dense plankton. What that means exactly is not yet understood.