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Aug.
16, 2007
CU-BOULDER RESEARCH GROUP FORECASTS 92 PERCENT CHANCE
OF RECORD
LOW ARCTIC SEA ICE
EXTENT IN 2007
University of Colorado at Boulder researchers are now forecasting a 92
percent
chance that the 2007 September minimum extent of sea ice across the
Arctic
region will set an all-time record low.
The researchers, who forecast in April a 33 percent chance the
September
minimum of sea ice would set a new record, dramatically revised their
prediction following a rapid disintegration of sea ice during July,
said
Research Associate Sheldon Drobot of CU-Boulder's Colorado
Center
for Astrodynamics.
"During the first week in July, the Arctic sea ice started to disappear
at
rates we had never seen before," said Drobot, who leads CCAR's Arctic
Regional Ice Forecasting System group in CU-Boulder's aerospace
engineering
sciences department.
"We have been seeing a sharp decline in thicker, multi-year ice that
has
survived more than one melt season," said CCAR Research Associate James
Maslanik. "This has been replaced in many areas by a thin, first-year
layer of ice as well as by younger, thinner types of multi-year ice.
The
thinner ice just does not have the mass to withstand the effects of
warming
climate."
The record low September minimum for sea ice, set in 2005, is 2.15
million
square miles, Drobot said. For 2007, the highest probability minimum
extent is
1.96 million square miles, although there is a 25 percent chance the
low will
fall to 1.88 million square miles and a 5 percent chance the September
sea-ice
extent will fall to 1.75 million square miles, he said.
Sea-ice extent -- the area of an ocean covered by at least 15 percent
of ice --
has been declining at least since the late 1970s, when concerted
satellite
measuring efforts began, said Drobot. The ongoing decline is believed
by many
researchers to be due primarily to higher temperatures due to warming
from
greenhouse gas emissions.
The factors triggering the unusually strong July sea-ice decline appear
to be a
combination of less multi-year ice and more cloud-free days, which
accelerated
the melting effects of solar radiation on the ice, Drobot said. "Things
can really change fast, which is why we continually update our
forecasts,"
he said.
The CCAR researchers used satellite data from the U.S. Department of
Defense
and temperature records from the National Oceanic and Atmospheric
Administration for the forecasts, which they have been producing for
five years,
said Drobot. The sea ice research by the CCAR group -- the only group
in the
world currently making seasonal Arctic sea ice forecasts based on
probability
-- is funded by the National Science Foundation and NASA, he said.
According to researcher Walt Meier of CU-Boulder's National Snow and Ice
Data Center,
the current sea
ice conditions are rapidly approaching the record daily minimum
already, with
at least a few more weeks of melting likely.
Arctic sea ice researchers pay particular attention to the months of
September
and March because they generally mark the annual minimum and maximum
sea ice
extents respectively, said Drobot.
Arctic sea ice is "one of the better predictors of climate change on
Earth," Drobot said. "There will probably be about two-thirds as much
sea this September as there was 25 years ago, a good indication that
something
significant is happening with the climate."
The Arctic sea ice decline has been sharpest in the western Arctic
over the past few years, said Drobot. Such regional variation is of
interest to
the maritime industry, including government agencies, international
shipping
companies, energy exploration corporations and tourism cruise lines
active in
the far North, he said.
"This type of information is useful for ship operators trying to plan
activities several months out," Drobot said. "It's also useful for
short-term operational planning, including cruise ship excursions."
Assuming the sea ice decline continues in the Arctic, there probably
will be a
significant amount of intercontinental "Northwest Passage" type of
transit from North America to places like Europe
in the coming decades, Drobot said. A seasonal or year-round, ice-free
channel
through the Arctic waters would be significantly shorter and more cost
effective than shipping through the Panama
Canal,
Drobot said.
##
Contact:
Sheldon Drobot
University
of Colorado
303-492-8143
sheldon.drobot@colorado.edu
This text derived from:
http://www.colorado.edu/news/releases/2007/298.html
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