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Posts Tagged ‘Greenland’

Large-Scale Assessment Of The Arctic Ocean: Significant Increase In Freshwater Content Since 1990s

March 28, 2011 Comments off

nanopatentsandinnovations

The freshwater content of the upper Arctic Ocean has increased by about 20 percent since the 1990s. This corresponds to a rise of approx. 8,400 cubic kilometres and has the same magnitude as the volume of freshwater annually exported on average from this marine region in liquid or frozen form. This result is published by researchers of the Alfred Wegener Institute in the journal Deep-Sea Research. The freshwater content in the layer of the Arctic Ocean near the surface controls whether heat from the ocean is emitted into the atmosphere or to ice. In addition, it has an impact on global ocean circulation.

Differences in the mean salinity of the Arctic Ocean above the 34 isohaline between 2006 to 2008 and 1992 to 1999.

Negative values are shown in yellow, green, and blue and stand for an increase of freshwater.

Image: Benjamin Rabe, Alfred Wegener Institute Read more…

Pace of polar ice melt ‘accelerating rapidly’: study

March 10, 2011 Comments off

 

(AFP)

WASHINGTON — The pace at which the Greenland and Antarctic ice sheets are melting is “accelerating rapidly” and raising the global sea level, according to findings of a study financed by NASA and published Tuesday.

The findings suggest that the ice sheets — more so than ice loss from Earth’s mountain glaciers and ice caps — have become “the dominant contributor to global sea level rise, much sooner than model forecasts have predicted.”

This study, the longest to date examining changes to polar ice sheet mass, combined two decades of monthly satellite measurements with regional atmospheric climate model data to study changes in mass.

“That ice sheets will dominate future sea level rise is not surprising — they hold a lot more ice mass than mountain glaciers,” said lead author Eric Rignot, jointly of NASA’s Jet Propulsion Laboratory and the University of California, Irvine.

“What is surprising is this increased contribution by the ice sheets is already happening,” he said.

Under the current trends, he said, sea level is likely to be “significantly higher” than levels projected by Read more…

UA climate research: Big stretch of US coast at risk of rising seas

February 23, 2011 Comments off

azstarnet.com

If global temperatures continue to rise and polar ice continues to melt, 9 percent of the land in our coastal cities and towns will be beneath sea level by the end of the century, University of Arizona researchers say.

Climate researchers Jeremy Weiss and Jonathan Overpeck, along with Ben Strauss of Climate Central in Princeton, N.J., mapped the U.S. coastline, using elevations provided by the U.S. Geological Survey. They applied the most recent predictions of a sea level rise of 1 meter (3.28 feet) by 2100 to produce a map that predicts big trouble for 20 cities with more than 300,000 people and for 160 smaller municipalities.

Weiss is a senior researcher in geosciences. Overpeck is a professor of geosciences and atmospheric sciences and co-director of the UA’s Institute of the Environment.

The report was published last week in Climatic Change Letters.

The biggest impact will be felt in low-lying, heavily populated places such as New Orleans, Miami Beach and Virginia Beach, the report says.

Subsequent centuries will bring even higher sea levels that could completely submerge Read more…

The What? And Why? Of Rare Earth Metals

February 10, 2011 1 comment

Over the past few months, there’s been a buzz surrounding rare earth metals. These are metals such as europium, lanthanum, neodymium and 14 others found in small concentrations attached to other metals and resource deposits. They’re actually not that rare, just expensive and difficult to pull out of the ground.

These naturally occurring elements are essential in everything from wind turbines to lasers to iPads.

Rare earths are a conundrum for the environmentally conscious—they hold the key to green energies but create toxic waste when being separated away from other elements. “Just one wind turbine generating 3 megawatts of electricity requires 600 kilograms of rare earths for its magnets,” a source told the United Kingdom’s Guardian newspaper.

Electric and hybrid cars can contain more than twice as much rare earth metals as a standard car. This image from the NY Times breaks down how these metals make up critical elements of a Prius.

Currently, China controls 97 percent of the world’s production of rare earth metals. In October 2010, the country cut exports of the metals by 70 percent, disrupting manufacturing in Japan, Europe and the U.S., and sending the prices of these metals up 40 percent.

China currently controls production but the country only has 37 percent of Read more…

The sun rises two days early in Greenland, sparking fears that climate change is accelerating

January 17, 2011 Comments off

The sun over Greenland has risen two days early, baffling scientists and sparking fears that Arctic icecaps are melting faster than previously thought.

Experts say the sun should have risen over the Arctic nation’s most westerly town, Ilulissat, yesterday, ending a month-and-a-half of winter darkness.

But for the first time in history light began creeping over the horizon at around 1pm on Tuesday – 48 hours ahead of the usual date of 13 January.

The mysterious sunrise has confused scientists, although it is believed the most likely explanation is that it is down to the lower height of melting icecaps allowing the sun’s light to penetrate through earlier.

Climate change? The sun rose in Ilulissat, Greenland, two days early on Tuesday, ending a month-and-a-half of winter darkness. One theory is that melting ice caps have lowered the horizon allowing the sun to shine through earlierClimate change? The sun rose in Ilulissat, Greenland, two days early on Tuesday, ending a month-and-a-half of winter darkness. One theory is that melting ice caps have lowered the horizon allowing the sun to shine Read more…