Arctic Sea Ice Area Below 2.4 Million Square Kilometers

Today Arctic sea ice measurements showed a new low for area at 2.37 million square kilometers, 533,000 square kilometers below the record low set last year.

Sea ice extent remained stable, holding near its new record low of 3.68 million square kilometers for JAXA and 3.54 million square kilometers for NSIDC.

Based on satellite observation, it appears that ice has spread slightly even as it thinned and new holes opened up, suggesting weather conditions consolidating the ice sheet have relaxed somewhat.

Melt rates have leveled off a bit over the past few days. If this slowing continues, we may finally see the natural abatement that leads up to the end of a typical melt season. Currently, such a call is too early to make, but it does appear possible.

Current ice loss totals below previous record lows are as follows (parenthesis show previous record year):

JAXA Extent: -572,000 square kilometers (2007)

Cryosphere Today Area: -533,000 square kilometers (2011)

PIOMAS Volume: -400 cubic kilometers (2011)

NSIDC Extent: -630,000 square kilometers (2007)

By all measures this is a crash year likely second only to 2007. It is part of a much larger trend of sea ice decline that started at the beginning of the 20th century and has accelerated since the 1970s, reaching a particularly rapid pace over the past 10 years.

There has been lots of chatter over the cryo blogosphere today about potentials for future melt and the reasons this melt season happened. In short, it’s the record melt that shouldn’t have been. All other things being normal, we would have seen the recovery climate change deniers kept pointing toward. But all other things are clearly not normal and a number of people are doing their best to expose the underlying trends.

One of the underlying trends involves the large loss of sea ice volume seen in 2007 and 2010. In his excellent analysis of sea ice volume loss for 2010, Chris Reynolds recently noted:

“To dismiss 2007 and 2010 as mere weather driven events is to ignore the crucial fact that the forcings driving sea ice loss are unremitting and are not giving the ice time to recover. As the ice gets thinner open water formation efficiency goes up and weather driven loss events become more likely.”

You can read Chris’s full blog on the subject here.

It is these underlying volume losses that set the stage for this year’s large sea ice area and extent losses. It is also valid proof that global warming forcings have reached a point that is not allowing the Arctic sea ice to recover.

Links:

http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi

http://arctic.atmos.uiuc.edu/cryosphere/

http://nsidc.org/

http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/

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