Re: Climate Change as Liberation Hydrology
On Aug 10, 2007, at 9:42 AM, Dwayne Monroe wrote:
In a subscriber-only article over at New Scientist, NASA climate scientist James Hansen describes what the planet might look like after a “runaway collapse” of the West Antarctic ice sheet.
New York Times - August 10, 2007 http://www.nytimes.com/2007/08/10/science/earth/10arctic.html
Analysts See ‘Simply Incredible’ Shrinking of Floating Ice in the Arctic By ANDREW C. REVKIN
The area of floating ice in the Arctic has shrunk more this summer
than in any other summer since satellite tracking began in 1979, and
it has reached that record point a month before the annual ice
pullback typically peaks, experts said yesterday.
The cause is probably a mix of natural fluctuations, like unusually
sunny conditions in June and July, and long-term warming from heat-
trapping greenhouse gases and sooty particles accumulating in the
air, according to several scientists.
William L. Chapman, who monitors the region at the University of
Illinois Urbana-Champaign and posted a Web report on the ice retreat
yesterday, said that only an abrupt change in conditions could
prevent far more melting before the 24-hour sun of the boreal summer
set in September. “The melting rate during June and July this year
was simply incredible,” Mr. Chapman said. “And then you’ve got this
exposed black ocean soaking up sunlight and you wonder what, if
anything, could cause it to reverse course.”
Mark Serreze, a sea-ice expert at the National Snow and Ice Data
Center in Boulder, Colo., said his center’s estimates differed
somewhat from those of the Illinois team, and by the ice center’s
reckoning the retreat had not surpassed the satellite-era record set
in 2005. But it was close even by the center’s calculations, he said,
adding that it is almost certain that by September, there will be
more open water in the Arctic than has been seen for a long time. Ice
experts at NASA and the University of Washington echoed his assessment.
Dr. Serreze said that a high-pressure system parked over the Arctic
appeared to have caused a “triple whammy” — keeping away clouds,
causing winds to carry warm air north and pushing sea ice away from
Siberia, exposing huge areas of open water.
The progressive summertime opening of the Arctic has intensified a
longstanding international tug of war over shipping routes and
possible oil and gas deposits beneath the Arctic Ocean seabed.
Last week, Russians planted a flag on the seabed at the North Pole.
On Wednesday, Stephen Harper, the Canadian prime minister, began a
tour of Canada’s Arctic holdings, pledging “to vigorously protect our
Arctic sovereignty as international interest in the region increases.”
http://arctic.atmos.uiuc.edu/cryosphere/
Thursday, August 9, 2007 - New historic sea ice minimum
Today, the Northern Hemisphere sea ice area broke the record for the
lowest recorded ice area in recorded history. The new record came a
full month before the historic summer minimum typically occurs. There
is still a month or more of melt likely this year. It is therefore
almost certain that the previous 2005 record will be annihilated by
the final 2007 annual minima closer to the end of this summer.
In previous record sea ice minima years, ice area anomalies were
confined to certain sectors (N. Atlantic, Beaufort/Bering Sea, etc).
The character of 2007’s sea ice melt is unique in that it is dramatic
and covers the entire Arctic sector. Atlantic, Pacific and even the
central Arctic sectors are showing large negative sea ice area
anomalies.
While we use sea ice concentration data supplied by NASA via the
National Snow and Ice Data Center (NSIDC), there are some differences
between the way we and NSIDC process our sea ice indices. NSIDC uses
10-day running means; we use 3-day running means. NSIDC will often
report sea ice extent indices and records, we are reporting a new sea
ice minima sea ice area. The ice area metric includes year-to-year
variations within the central pack ice and not just variations in the
southern sea ice edge. Regardless of these differences, the rapid
rate of sea ice melt this summer, along with the current negative sea
ice anomalies almost guarantees a record Northern Hemisphere summer
sea ice minimum this summer, by any metric.