"Stop the presses! Arctic melt ain’t over ’til it’s over."
So the fat lady sang, but I guess she hit just the right note and shattered some more ice. Or it could be those pesky greenhouse gases, which always seem to be causing trouble….
That plot is from the Japan Aerospace Exploration Agency (click to enlarge), whose latest value for sea ice extent (yesterday) is 4,832,813 km2. There appears to be a chance JAXA’s extent will drop below the 2008 level.
Their data for the last ten days shows how sharp this new downturn is:
09,07,2010: 5027188 09,08,2010: 4989375 09,09,2010: 4972656 09,10,2010: 4952813 09,11,2010: 4986406 09,12,2010: 5005000 09,13,2010: 5008750 09,14,2010: 4998594 09,15,2010: 4948438 09,16,2010: 4890938 09,17,2010: 4832813
UPDATE: The National Snow and Ice Data Center, which tentatively called a minimum a few days ago, now shows a full double dip [note — the image below updates daily]:
JAXA explains how it differs from NSIDC:
In general, sea-ice extent is defined as a temporal average of several days (e.g., five days) in order to eliminate calculation errors due to a lack of data (e.g., for traditional microwave sensors such as SMMR and SSM/I). However, we adopt the average of two days to achieve rapid data release. The wider spatial coverage of AMSR-E enables reducing the data-production period.
NSIDC uses the less volatile five-day average, which bottomed out first on September 10 at 4.72.
The sea ice area picture seems a little muddier:
I can’t find the actual data for this plot. If anyone knows where it is, please post the link.
NSIDC told me that as of Wednesday, it’s “only in the E. Siberian Sea where you’ve had consistent ice growth over the last few days, whereas the other seas still show decreases, or oscillate between increases and decreases.”
So it seems possible to me that volume never went back up and could possibly have continued declining, as the thicker ice continued to be melted from underneath. But there is no real way of knowing at this point.
- Exclusive: Scientists track sharp drop in oldest, thickest Arctic sea ice.
- Arctic non-shocker: Ever-thinning sea ice melts out as area, extent, and volume approach record lows
- Serreze: Arctic is “continuing down in a death spiral. Every bit of evidence we have says the ice is thinning.”
- Major analysis finds “less ice covers the Arctic today than at any time in recent geologic history.”