Now that showed the Antarctic Sea Ice, it's time to check out the Arctic region.
The images below show the minimum sea ice extent during the month of September in 1999 and 2008 below it. They also show the Arctic sea ice maximum during the month of March in 1999 on the top right and 2009 below it.
Clearly, you can see that the greatest differences between the 1999/2000 and 2008/2009 season are during the sea ice minimum in September. You can also animate the images of all years since 1999 by clicking the play button on the Earth Observatory page.
The yellow outline on each image shows the median sea ice extent observed by satellite sensors in September and March from 1979 through 2000.
Since 1978, satellites have detected an overall decline in Arctic sea ice. The rate of decline steepened after the turn of the twenty-first century.
A key statement from the NASA article......
Cycles of natural variability such as the Arctic Oscillation are known to play a role in Arctic sea ice extent, but the sharp decline seen in this decade cannot be explained by natural variability alone. Natural variability and greenhouse gas emissions (and the resulting rise in global temperatures) likely worked together to melt greater amounts of Arctic sea ice.
This time series is made from a combination of observations from the Special Sensor Microwave/Imagers (SSM/Is) flown on a series of Defense Meteorological Satellite Program missions and the Advanced Microwave Scanning Radiometer for EOS (AMSR-E), a Japanese-built sensor that flies on NASAâ€™s Aqua satellite, according to the NASA Earth Observatory article.