Tag Archives: Arctic sea ice

NASA Finds Sea Ice Driving Arctic Air Pollutants

PASADENA, Calif. – Drastic reductions in Arctic sea ice in the last decade may be intensifying the chemical release of bromine into the atmosphere, resulting in ground-level ozone depletion and the deposit of toxic mercury in the Arctic, according to a new NASA-led study.

The connection between changes in the Arctic Ocean’s ice cover and bromine chemical processes is determined by the interaction between the salt in sea ice, frigid temperatures and sunlight. When these mix, the salty ice releases bromine into the air and starts a cascade of chemical reactions called a “bromine explosion.” These reactions rapidly create more molecules of bromine monoxide in the atmosphere. Bromine then reacts with a gaseous form of mercury, turning it into a pollutant that falls to Earth’s surface. (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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Russian River Water Unexpected Culprit Behind Arctic Freshening

A hemispherewide phenomenon – and not just regional forces – has caused record-breaking amounts of freshwater to accumulate in the Arctic’s Beaufort Sea.

Frigid freshwater flowing into the Arctic Ocean from three of Russia’s mighty rivers was diverted hundreds of miles to a completely different part of the ocean in response to a decades-long shift in atmospheric pressure associated with the phenomenon called the Arctic Oscillation, according to findings published in the Jan. 5 issue of Nature. (more…)

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Arctic Sea Ice Reaches Minimum 2011 Extent, the Second Lowest in the Satellite Record

The blanket of sea ice that floats on the Arctic Ocean appears to have reached its lowest extent for 2011, the second lowest recorded since satellites began measuring it in 1979, according to the University of Colorado Boulder’s National Snow and Ice Data Center.

The Arctic sea ice extent fell to 1.67 million square miles, or 4.33 million square kilometers on Sept. 9, 2011. This year’s minimum of 1.67 million square miles is more than 1 million square miles below the 1979-2000 monthly average extent for September — an area larger than Texas and California combined. (more…)

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Measurements of Winter Arctic Sea Ice Show continuing Ice Loss, says CU-Boulder Study

The 2011 Arctic sea ice extent maximum that marks the beginning of the melt season appears to be tied for the lowest ever measured by satellites, say scientists at the University of Colorado Boulder’s National Snow and Ice Data Center.

The CU-Boulder research team believes the lowest annual maximum ice extent of 5,650,000 square miles occurred on March 7. The maximum ice extent was 463,000 square miles below the 1979-2000 average, an area slightly larger than the states of Texas and California combined. The 2011 measurements were tied with those from 2006 as the lowest maximum sea ice extents measured since satellite record keeping began in 1979. (more…)

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Warming North Atlantic Water Tied to Heating Arctic, According to New Study

The temperatures of North Atlantic Ocean water flowing north into the Arctic Ocean adjacent to Greenland — the warmest water in at least 2,000 years — are likely related to the amplification of global warming in the Arctic, says a new international study involving the University of Colorado at Boulder.

Led by Robert Spielhagen of the Academy of Sciences, Humanities and Literature in Mainz, Germany, the study showed that water from the Fram Strait that runs between Greenland and Svalbard — an archipelago constituting the northernmost part of Norway — has warmed roughly 3.5 degrees Fahrenheit in the past century. The Fram Strait water temperatures today are about 2.5 degrees F warmer than during the Medieval Warm Period, which heated the North Atlantic from roughly 900 to 1300 and affected the climate in Northern Europe and northern North America. (more…)

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Projected Losses of Arctic Sea-Ice and Polar Bear Habitat may be Reduced if Greenhouse Gas Emissions are Stabilized

ANCHORAGE, Alaska – Sea-ice habitats essential to polar bears would likely respond positively should more curbs be placed on global greenhouse gas emissions, according to a new modeling study published in the journal, Nature

The study, led by the U.S. Geological Survey, included university and other federal agency scientists. The research broke new ground in the “tipping point” debate in the scientific community by providing evidence that during this century there does not seem to be a tipping point at which sea-ice loss would become irreversible.  (more…)

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