New data from Japan’s GCOM-W1 satellite show that the 2014 Arctic
sea ice minimum is the sixth lowest minimum sea ice extent recorded in
the satellite era. A short animation shows the daily Arctic sea ice
extent from March 21, 2014 to September 17, 2014.
An animation of daily Arctic sea ice extent from March 21 to
September 17 – when the ice appeared to reach it’s minimum extent for
the year. It’s the sixth lowest minimum sea ice extent in the satellite
era. The data was provided by the Japan Aerospace Exploration Agency.
Credit: NASA Goddard’s Scientific Visualization Studio/Trent Schindler
Arctic sea ice coverage continued its below-average trend this year
as the ice declined to its annual minimum on Sept. 17, according to the
NASA-supported National Snow and Ice Data Center (NSIDC) at the
University of Colorado, Boulder.
“Arctic sea ice coverage in 2014 is the sixth lowest recorded since
1978,” said Walter Meier, a research scientist at NASA’s Goddard Space
Flight Center in Greenbelt, Maryland.
Over the 2014 summer, Arctic sea ice melted back from its maximum
extent reached in March to a coverage area of 1.94 million square miles
(5.02 million square kilometers), according to analysis from NASA and
NSIDC scientists. This year’s minimum extent is similar to last year’s
and below the 1981-2010 average of 2.40 million square miles (6.22
million square km).
“The summer started off relatively cool, and lacked the big storms or
persistent winds that can break up ice and increase melting,” said
Meier. Nevertheless, the season ended with below-average sea ice. “Even
with a relatively cool year, the ice is so much thinner than it used to
be. It is more susceptible to melting,” he explained.
This summer, the Northwest Passage above Canada and Alaska remained
ice-bound. A finger of open water stretched north of Siberia in the
Laptev Sea, reaching beyond 85 degrees north, which is the farthest
north open ocean has reached since the late 1970s, according to Meier.
While summer sea ice has covered more of the Arctic in the last two
years than in 2012’s record low summer, this is not an indication that
the Arctic is returning to average conditions, Meier said. This year’s
minimum extent remains in line with a downward trend; the Arctic Ocean
is losing about 13 percent of its sea ice per decade.
To measure sea ice extent, scientists include areas that are at least
15 percent ice-covered. The NASA-developed computer analysis, which is
one of several methods scientists use to calculate extent, is based on
data from NASA’s Nimbus 7 satellite, which operated from 1978 to 1987,
and the U.S. Department of Defense’s Defense Meteorological Satellite
Program, which has provided information since 1987.
In addition to monitoring sea ice from space, NASA is conducting
airborne field campaigns to track changes in Arctic sea ice and its
impact on climate. Operation IceBridge flights have been measuring
Arctic sea ice and ice sheets for the past several years during the
spring. A new field experiment, the Arctic Radiation – IceBridge Sea and
Ice Experiment (ARISE) started this month to explore the relationship
between retreating sea ice and the Arctic climate.
For more information on sea ice observations from space, visit http://nsidc.org/data/seaice/
Source: Dr. Tony Phillips, Science@NASA
Image: NASA Goddard’s Scientific Visualization Studio/Trent Schindler,src http://scitechdaily.com
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