We have news from the National Snow and Ice Data Center (NSIDC).
They say: The melt is over. And we’ve added 9.4% ice coverage
from this time last year. Though it appears NSIDC is attempting
to downplay this in their web page announcement today, one can safely
say that despite irrational predictions seen earlier this year,
we didn’t reach an “ice free north pole” nor a
new record low for sea ice extent.
Here is the current sea ice extent graph from NSIDC as of today,
notice the upturn, which has been adding ice now for 5 days:
Here is what they have to say about it:
The Arctic sea ice cover appears
to have reached its minimum extent for the year, the second-lowest
extent recorded since the dawn of the satellite era. While above
the record minimum set on September 16, 2007, this year further
reinforces the strong negative trend in summertime ice extent observed
over the past thirty years. With the minimum behind us, we will
continue to analyze ice conditions as we head into the crucial period
of the ice growth season during the months to come.
Despite overall cooler summer temperatures, the 2008 minimum
extent is only 390,000 square kilometers (150,000 square miles),
or 9.4%, more than the record-setting 2007 minimum. The 2008 minimum
extent is 15.0% less than the next-lowest minimum extent set in
2005 and 33.1% less than the average minimum extent from 1979
Overlay of 2007 and 2008 at September
The spatial pattern of the 2008 minimum extent was different
than that of 2007. This year did not have the substantial ice
loss in the central Arctic, north of the Chukchi and East Siberian
Seas. However, 2008 showed greater loss in the Beaufort, Laptev,
and Greenland Seas.
Unlike last year, this year saw
the opening of the Northern Sea Route, the passage through the Arctic
Ocean along the coast of Siberia. However, while the shallow Amundsen’s
Northwest Passage opened in both years, the deeper Parry’s
Channel of the Northwest Passage did not quite open in 2008.
A word of caution on calling the minimu
Determining with certainty when the minimum has occurred is difficult
until the melt season has decisively ended. For example, in 2005,
the time series began to level out in early September, prompting
speculation that we had reached the minimum. However, the sea
ice contracted later in the season, again reducing sea ice extent
and causing a further drop in the absolute minimum.
We mention this now because the natural variability of the climate
system has frequently been known to trick human efforts at forecasting
the future. It is still possible that ice extent could fall again,
slightly, because of either further melting or a contraction in
the area of the pack due to the motion of the ice. However, we
have now seen five days of gains in extent. Because of the variability
of sea ice at this time of year, the National Snow and Ice Data
Center determines the minimum using a five-day running mean value.
Ongoing analysis continues
We will continue to post analysis of sea ice conditions throughout
the year, with frequency determined by sea ice conditions. Near-real-time
images at upper right will continue to be updated every day.
In addition, NSIDC will issue
a formal press release at the beginning of October with full analysis
of the possible causes behind this year’s low ice conditions,
particularly interesting aspects of the melt season, the set-up
going into the important winter growth season ahead, and graphics
comparing this year to the long-term record. At that time, we will
also know what the monthly average September sea ice extent was
in 2008—the measure scientists most often rely on for accurate
analysis and comparison over the long-term.
It will be interesting to see what they offer in the October press
release. Plus we’ll be watching how much ice we add this winter,
and what next year’s melt season will look like. Hopefully
we won’t have a new crop of idiots like Lewis Gordon Pugh
trying to reach the “ice free north pole” next year.