Arctic ice extent continues downwards on the trend line started at the end of March, having lost a little over 1,000,000 km2 during April. If that linear rate continues, the Arctic will be ice free around January 1, 2011. That would be a complete disaster for Santa Claus and the billions of people who depend on him.
During the past month, Arctic sea ice has straddled between the NSIDC 1979-2000 average (wide black line) and the NSIDC 1979-2009 average (wide turquoise line.) The composite image below shows all four commonly used extent graphs – NSIDC/NORSEX/DMI/JAXA . The thin turquoise line is NSIDC 2009. Note that the melt season is about three weeks behind the 2007 extent (dashed) line.
During the last few days, ice has begun to disappear from the Barents Sea. The modified NSIDC map below shows loss of ice from one week ago, marked in red. I wonder if any soot from Iceland is dirtying the ice? Hansen says that soot may be responsible for 25% of all global warming.
The UIUC graph below provides a more detailed blow by blow of what is happening to ice area in the Barents Sea.
The modified NSIDC map below shows loss of ice since the first week in April, marked in red.
The modified NSIDC map below shows changes in ice since May 2, 2007. Green areas have more ice, and red areas have less ice.
The modified NSIDC map below shows areas of above “normal” (green) and below “normal” (red) ice. The western Arctic is above average, and the eastern Arctic is below average. Perhaps all the hot air from Copenhagen in December thinned the ice?
During the past few summers, the low anomalies have been on the western side of the Arctic. Note in the SST map below, that ocean temperatures are abnormally cold on the western side, which is likely to slow melt this summer.
The Arctic Oscillation is forecast to go negative again, which should inhibit melt in the Arctic and growth in my garden.
We are still about eight weeks away from the beginning of the really interesting melt season. Stay tuned. The Antarctic remains boring, staying average to slightly above. No meltdowns or collapsing ice sheets to report this week.