This year both passages are open
and this is no longer exceptional. In
fact this year there was no special circumstances that I am aware of as was the
case in 2007 when the winds actually concentrated the ice. Today a lot less ice is now covering the same
area as 2007. A return of the 2007 wind
regime would have produced a dramatic reduction in area this year.
In fact over the past five years
we have continued to lose ice at much the same pace contrary to what the navy
has been reporting from submarine work.
I hate throwing their data away, but in the end our eyes are saying
something else altogether.
I do not think we have reached a
natural minimum as yet, but I do think we are rather close.
Back in 2007, I predicted that we
would possibly hit that bottom by 2012.
We are actually doing pretty well.
The rotation of the gyre keeps ice around for about three years at most. Thus the present low for multi year ice needs
to be understood. Does it even properly
exist at present?
The sea ice is breaking up enough
to ensure little sea ice will succeed in making two trips around the gyre. The scientific question today is to determine
just how much.
The good news is that such broken
up ice could be navigated with huge air cushioned ships which have the capacity
to lift and shatter any ice in its path.
Large ships so configured could traverse such an icy sea even in winter
as the maximum strength would be a few feet rather than tens of feet acquired
over years.
Obviously the passages are
essentially open for some traffic.
Arctic sea routes open as ice melts
By Richard BlackEnvironment correspondent, BBC News
25 August 2011 Last updated at 12:42 ET
Two major Arctic shipping routes have opened as summer sea ice melts,
European satellites have found.
Data recorded by the European Space Agency's (Esa) Envisat shows both Canada 's Northwest Passage and Russia 's Northern Sea Route open simultaneously.
This summer's melt could break the 2007 record for the smallest area of
sea ice since the satellite era began in 1979.
Shipping companies are already eyeing the benefits these routes may
bring if they remain open regularly.
The two lanes have been used by a number of small craft several times
in recent years.
But the Northern Sea Route
has been free enough of ice this month for a succession of tankers carrying
natural gas condensate from the northern port
of Murmansk to sail along the Siberian
coast en route for Thailand .
"They're often open at the same time in the sense that with some
ingenuity you can get through them," observed Peter Wadhams, an Arctic ice
expert from the University
of Cambridge .
This year again confirms that we are in a new regime with substantially
less summer ice”
Leif Toudal PedersenDanish Meteorological Institute
"But this time they've really been open, with a proper Suez-size
tanker going through the Northern Sea Route with a full cargo - that's a real
step forward," he told BBC News.
A number of major shipping companies are looking to the opening of
these routes to shorten journey times and make their businesses more efficient.
But environmental groups are concerned that the progressive ice loss
will lead to increased exploration for oil and gas.
This, they argue, presents major safety hazards in the often inclement
Arctic, as well as strengthening the world's reliance on fossil fuels and so
ensuring the progression of man-made global warming - and the disintegration of
summer sea ice cover.
The Arctic sea ice has been melting fast this year, and for a while it
appeared set to break the 2007 record for the smallest minimum area in the
satellite record.
However, in recent weeks it has been running a narrow second to 2007.
"The minimum ice extent is still three to four weeks away, and a
lot depends on the weather conditions over the Arctic
during those weeks," said Leif Toudal Pedersen, senior scientist at the
Danish Meteorological Institute.
"Whether we reach an absolute minimum or not, this year again
confirms that we are in a new regime with substantially less summer ice than
before.
"The last five summers are the five minimum ice extent summers on
record."
The volume of sea ice continues to decline annually.
Professor Wadhams believes the advent of summers where the two sea
routes are routinely open is not far away.
"The Northwest Passage is
probably the less reliable becaise you've got so many small passages in it
where chance variations in wind will pile ice up and block it," he said.
"But so long as the ice retreats from the coast of Siberia , you'll have a route there."
Some computer models forecast that the Arctic
could be completely clear of summer sea ice within a decade, though others
recently published say there may be high years and low years en route to the
final disappearance.
No comments:
Post a Comment