This astounding video animation by Nasa shows the dramatic ice melt in the arctic from 1979 to September 2007. The 2007 Arctic summer sea ice has reached the lowest extent of perennial ice cover on record - nearly 25% less than the previous low set in 2005.
The area of the perennial ice has been steadily decreasing since the satellite record began in 1979, at a rate of about 10% per decade. But the 2007 minimum, reached on September 14, is far below the previous record made in 2005 and is about 38% lower than the climatological average. Such a dramatic loss has implications for ecology, climate and industry.
Sea ice is frozen seawater floating on the surface of the ocean. Some sea ice is semi-permanent, persisting from year to year, and some is seasonal, melting and refreezing from season to season. The sea ice cover reaches its minimum extent at the end of each summer and the remaining ice is called the perennial ice cover.
About this winter the Nasa researchers using the latest satellite observations has reported yesterday that the Arctic is still on “thin ice” when it comes to the condition of sea ice cover in the region. A colder-than-average winter in some regions of the Arctic this year has yielded an increase in the area of new sea ice, while the older sea ice that lasts for several years has continued to decline. They believe that the increased area of sea ice this winter is due to recent weather conditions, while the decline in perennial ice reflects the longer-term warming climate trend and is a result of increased melting during summer and greater movement of the older ice out of the Arctic.
read more about this news on NASA.gov
1979 to 1981 average - ©Nasa
2003 to 2005 average - ©Nasa