Antarctic sea ice retreat could set stage for ice shelf collapses
Staff ReportMonths of above-average temperatures in the Arctic slowed the growth of sea ice formation to a crawl during the second half of October, the National Snow and Ice Data Center reported in its latest monthly update.The ice scientists said that, starting Oct. 20, Arctic sea ice started setting daily record lows for extent. After mid-October, ice growth returned to near-average rates, but extent remained at record low levels through late October. Both sea surface and air temperatures have remained unusually high, extending from the surface high up into the atmosphere. Continue reading “Climate: Sea ice at both poles way below average”→
Melt season is 2 to 4 weeks ahead of 2012, which set record for low extent
Arctic sea ice extent continues to track toward a record low, the National Snow and Ice Data Center reported last week, resuming regular updates of sea ice after switching to a new satellite for the measurements.
As of June 7, the sea ice meltdown was ahead of 2012 by two to four weeks. Sea ice extent hit a record low that year and has been near that level every year since. The past two years, it set new record-lows for winter extent.
After a winter that saw average temperatures across most of the Arctic hover between 4 to 11 degrees Fahrenheit above average, sea ice in the region peaked at a record low extent for the second year in a row.
“I’ve never seen such a warm, crazy winter in the Arctic,” National Snow and Ice Data Center director Mark Serreze said in a press release that also explained how this year’s maximum sea ice extent came much later than average. See the full NSIDC report here.
Winter brings extraordinary ‘heatwave’ to the far north
Arctic sea ice was at a record low extent for the second month in a row in February, according to the National Snow and Ice Data Center. Ice researchers said sea ice grew hardly at all during the first three weeks of the month during a time of year when the sea is extent is usually nearing its peak.
Arctic sea ice extent in January was the lowest in the satellite record, according to the latest monthly update from the National Snow and Ice Data Center. Scientists said the new record monthly low was likely the result of unusually high air temperatures over the Arctic Ocean and a strong negative phase of the Arctic Oscillation for the first three weeks of the month.
Meanwhile in the Antarctic, this year’s extent was lower than average for January, in contrast to the record high extents in January 2015.
In the Arctic, the ice extent average 5.2 million square miles, 402,000 square miles below the 1981 to 2010 average and 35,000 square miles below the previous record January low that occurred in 2011.
Across most of the Arctic Ocean, air temperatures ran more than 13 degrees above average for most of January as a cyclical air pressure shift enabled warm air to flow northward toward the Arctic.
Over the long term, January sea ice extent is shrinking at a rate of about 3.2 percent per decade. Sea ice extent has been below 14.25 million square miles every year since 2005, according to the NSIDC.
But some projections suggest that winter sea ice extent could hold steady or even increase in the short term because of changes in a key Atlantic Ocean current that transports cold water northward. Observational data show a slight upward trend in Arctic sea ice extent from 2005 to 2015.