Arctic ice in death spiral
June 8th, 2010 by Jim JustThe National Snow and Ice Data Center (NSIDC) reports that by the end of May, Arctic ice extent had fallen to near the 2006 level, the lowest in the satellite record for the end of that month.
NSIDC explains why Arctic ice went so rapidly from near normal to approach record lows:
[S]everal regions of the Arctic experienced a late-season spurt in ice growth. As a result, ice extent reached its seasonal maximum much later than average, and in turn the melt season began almost a month later than average. As ice began to decline in April, the rate was close to the average for that time of year. In sharp contrast, ice extent declined rapidly during the month of May. Much of the ice loss occurred in the Bering Sea and the Sea of Okhotsk, indicating that the ice in these areas was thin and susceptible to melt. Many polynyas, areas of open water in the ice pack, opened up in the regions north of Alaska, in the Canadian Arctic Islands, and in the Kara and Barents and Laptev seas.
The polynyas are clearly visible in high-resolution passive microwave images from the Advanced Microwave Sounding Radiometer (AMSR-E) aboard NASA’s Aqua satellite. What do current ice conditions mean for the minimum ice extent this fall? It is still too soon to say: although ice extent at present is relatively low, the amount of ice that survives the summer melt season will be largely determined by the wind and weather conditions over the next few months.
Analysis from scientists at the University of Washington shows that ice volume has continued to decline precipitously.
- Continuously updated Arctic Sea Ice Volume Anomaly from PIOMAS. Daily Sea Ice volume anomalies for each day are computed relative to the 1979 to 2009 average for that day. The trend for the 1979- present period is shown in blue. Shaded areas show one and two standard deviations from the trend.
Joseph Romm comments at Climate Progress on a presentation by Wieslaw Maslowski of the Naval Postgraduate School, one of the country’s leading experts on the Arctic, indicating the Arctic is in a death spiral. By 2016 (+/- 3 yrs) the Arctic will be essentially ice-free by the end of the melt season – decades ahead of the projections in the 2007 IPCC report.
And here’s the latest multi-year chart of Arctic ice extent from the Japan Aerospace Exploration Agency website.
