NSIDC Arctic sea ice news May 2010

NSIDC has finally issued their May report with a summary of what has happened in the previous month. The polar scientists in Colorado deem it too soon to be talking about 'death spirals' and such, and right they are.

Some excerpts:

At the end of the month, extent fell near the level recorded in 2006, the lowest in the satellite record for the end of May.

The rate of decline through the month of May was the fastest in the satellite record; the previous year with the fastest daily rate of decline in May was 1980. By the end of the month, extent fell near the level recorded in 2006, the lowest in the satellite record for the end of May. Despite the rapid decline through May, average ice extent for the month was only the ninth lowest in the satellite record.

Arctic air temperatures averaged for May were above normal, continuing the temperature trend that has persisted since last winter. Temperatures were 2 to 5 degrees Celsius (4 to 9 degrees Fahrenheit) above average across much of the Arctic Ocean.

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.

And a graph:

 

UPDATE: Read Patrick Lockerby's take on the NSIDC report for May. From his conclusion:

About 50% of the sea ice is, as of this date, highly mobile due to failure to consolidate or to fragmentation of consolidated pack.  As areas of open water extend, there is a tendency for continuous areas of fragmented ice to expand into that open water due to lateral pressures and impacts within the pack.  This can mask ice loss as measured by extent for as long as the area within the pack edge contains more than 15% ice.

Given that the reality is warmer water due to the loss of albedo, it may happen that an area showing a fairly steady 'extent' will exhibit a 'sudden and dramatic' ice loss according to collected data.  The ice loss in terms of volume will in fact be at a fairly steady rate until the real 'sudden ice loss' shows up as the rapid melting of the last remaining fragments in an otherwise open and warming area.