Tag Archives: Arctic sea ice

NASA: Warm Rivers Play Role in Arctic Sea Ice Melt

The heat from warm river waters draining into the Arctic Ocean is contributing to the melting of Arctic sea ice each summer, a new NASA study finds.

A research team led by Son Nghiem of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., used satellite data to measure the surface temperature of the waters discharging from a Canadian river into the icy Beaufort Sea during the summer of 2012. They observed a sudden influx of warm river waters into the sea that rapidly warmed the surface layers of the ocean, enhancing the melting of sea ice. A paper describing the study is now published online in the journal Geophysical Research Letters. (more…)

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Northern hemisphere losing last dry snow region, says CU study

Last July, something unprecedented in the 34-year satellite record happened: 98 percent of the Greenland Ice Sheet’s surface melted, compared to roughly 50 percent during an average summer. Snow that usually stays frozen and dry turned wet with melt water. Research led by the Cooperative Institute for Research in Environmental Sciences now shows last summer’s extreme melt could soon be the new normal.

“Greenland is warming rapidly, and such ice-sheet-wide, surface-melt events will occur more frequently over the next couple of decades,” said Dan McGrath, a University of Colorado Boulder doctoral student who works at CIRES. McGrath is lead author of a paper published online May 20 in Geophysical Research Letters and which reports a significant warming trend on the Greenland Ice Sheet. (more…)

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European Satellite Confirms UW Numbers: Arctic Ocean is on Thin Ice

The September 2012 record low in Arctic sea-ice extent was big news, but a missing piece of the puzzle was lurking below the ocean’s surface. What volume of ice floats on Arctic waters? And how does that compare to previous summers? These are difficult but important questions, because how much ice actually remains suggests how vulnerable the ice pack will be to more warming.

New satellite observations confirm a University of Washington analysis that for the past three years has produced widely quoted estimates of Arctic sea-ice volume. Findings based on observations from a European Space Agency satellite, published online in Geophysical Research Letters, show that the Arctic has lost more than a third of summer sea-ice volume since a decade ago, when a U.S. satellite collected similar data. (more…)

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CryoSat-2 Mission Reveals Major Arctic Sea-Ice Loss

Arctic sea ice volume has declined by 36 per cent in the autumn and 9 per cent in the winter between 2003 and 2012, a UK-led team of scientists has discovered.

Researchers from the Centre for Polar Observation and Modelling at UCL used new data from the European Space Agency’s CryoSat-2 satellite spanning 2010 to 2012, and data from NASA’s ICESat satellite from 2003 to 2008 to estimate the volume of sea ice in the Arctic. (more…)

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‘House Hunters Walrus’

UD camera system records sea ice, identifies ideal walrus habitats

About the video: A University of Delaware research team led by Chandra Kambhamettu has developed a novel camera system to map the surface topography of Arctic sea ice, identifying the best “homes” for walrus.

Walrus use sea ice as a reproductive, migration and resting habitat. However, as sea ice melts and recedes, this marine mammal increasingly is threatened. (more…)

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USGS Study Tracks Pacific Walrus, Observes Effects of Arctic Sea Ice Loss on Behavior

ANCHORAGE, Alaska — Sparse summer sea ice in the Arctic over the past five years has caused behavioral changes in Pacific walruses according to research published by U.S. Geological Survey and Russian scientists. The effects on the walrus population are unknown.

“The loss of sea ice is the ‘why’ for the change in walrus behavior; the tracking data tells us the ‘where’ in terms of their new forage patterns,” said USGS Director Marcia McNutt. “What awaits to be seen is ‘how much will it matter?'” (more…)

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Study Finds Surprising Arctic Methane Emission Source

The fragile and rapidly changing Arctic region is home to large reservoirs of methane, a potent greenhouse gas. As Earth’s climate warms, the methane, frozen in reservoirs stored in Arctic tundra soils or marine sediments, is vulnerable to being released into the atmosphere, where it can add to global warming. Now a multi-institutional study by Eric Kort of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., has uncovered a surprising and potentially important new source of Arctic methane: the ocean itself. (more…)

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New CU-led Study May Answer Long-Standing Questions About Enigmatic Little Ice Age

A new University of Colorado Boulder-led study appears to answer contentious questions about the onset and cause of Earth’s Little Ice Age, a period of cooling temperatures that began after the Middle Ages and lasted into the late 19th century.

According to the new study, the Little Ice Age began abruptly between A.D. 1275 and 1300, triggered by repeated, explosive volcanism and sustained by a self- perpetuating sea ice-ocean feedback system in the North Atlantic Ocean, according to CU-Boulder Professor Gifford Miller, who led the study. The primary evidence comes from radiocarbon dates from dead vegetation emerging from rapidly melting icecaps on Baffin Island in the Canadian Arctic, combined with ice and sediment core data from the poles and Iceland and from sea ice climate model simulations, said Miller. (more…)

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