Posted on November 23, 2013 by Bob Berwyn
‘Warmer summers will still lead to more rapid melting of the ice sheet …’
By Summit Voice
FRISCO — After examining a broad swath of the Greenland Ice Sheet, a science team led by University of Edinburgh researchers say they have a better understanding of how glacier movement is affected by melting ice in summer. That could lead to more accurate predictions of sea level rise.
The researchers gathered detailed GPS ice flow data and ice surface melt rates along a 115 kilometer transect in west Greenland and compared ice motion from an average melt year, 2009, with the exceptionally warm year of 2012.
The study, carried out in collaboration with the Universities of Sheffield, Aberdeen, Tasmania and Newcastle, was published in Proceedings of the National Academy of Sciences and supported by the Natural Environment Research Council.
“Although the record summer melt did not intensify ice motion, warmer summers will still lead to more rapid melting of the ice sheet,” said Professor Peter Nienow, of the University of Edinburgh’s School of GeoSciences, who led the study. “Furthermore, it is important that we continue to investigate how glaciers that end in the ocean are responding to climate change.” Continue reading
Filed under: Arctic, climate and weather, global warming, Greenland | Tagged: climate, global warming, Greenland ice sheet, sea level rise | Leave a comment »
Posted on November 2, 2013 by Bob Berwyn
Surface measurements will provide baseline data for upcoming satellite mission
Click on the image for more information on Greenland’s thinning ice cap.
By Summit Voice
FRISCO — A new airborne research effort by NASA will help measure ice loss in the Arctic by measuring changes in the height of the Greenland ice sheet and surrounding Arctic sea ice produced by a single season of summer melt.
The survey flights, running through Nov. 16, will collect data to improve the understanding of seasonal melt and provide baseline measurements for future satellite missions.
The land and sea ice data gathered during this campaign will give researchers a more comprehensive view of seasonal changes and provide context for measurements that will be gathered during NASA’s ICESat-2 mission, which is scheduled for launch in 2016. Continue reading
Filed under: climate and weather, Greenland | Tagged: global warming, Greenland ice sheet, IceSat-2, NASA | 1 Comment »
Posted on September 2, 2013 by Bob Berwyn
Radar data deciphers topography beneath the ice
By Summit Voice
FRISCO — Someday, if the Greenland ice cap melts because of global warming, tourists may have a new destination to rival the Grand Canyon.
After studying data from NASA’s Operation IceBridge, geographers at the University of Bristol in the United Kingdom said they found evidence of 460-mile canyon hidden under a mile of Greenland ice. In places, the previously undiscovered canyon is 2,600 feet deep. The huge gash is thought to predate the ice sheet that has covered Greenland for the last few million years.
“One might assume that the landscape of the Earth has been fully explored and mapped,” said Jonathan Bamber, professor of physical geography at the University of Bristol in the United Kingdom, and lead author of the study. “Our research shows there’s still a lot left to discover.” Continue reading
Filed under: Arctic, Greenland | Tagged: Bristol University, geography, greenland, Greenland ice sheet, NASA, Operation IceBridge, Petermann Glacier | Leave a comment »
Posted on August 8, 2013 by Bob Berwyn
The surface of Greenland’s ice sheet is growing darker, leading to more melting, but the ice is also melting from beneath because of heat rising from the Earth’s mantle. Image courtesy NASA Earth Observatory.
Study says basal melting should be factored into climate modelsBy Summit VoiceFRISCO — While all eyes have been on the surface of he Greenland ice sheet and its outlet glaciers in recent years, it turns out the ice is also melting at the bottom, heated by a high heat
flow from the mantle into the lithosphere (essentially the crust and the upper mantle). An international research team led by the GFZ German Research Centre for Geosciences concluded that the thinness of the Earth’s crust beneath Greenland enables an increase flow of heat from the mantle, but the effects on the Greenland ice sheet are highly variable. Continue reading
Filed under: climate and weather, Environment, Greenland | Tagged: Environment, Greenland ice sheet, Greenland ice sheet melting, sea level rise | 2 Comments »
Posted on August 4, 2013 by Bob Berwyn
Ice sheet surface melting above average in July
A graph from the Greenland Today website shows 2013 surface melting in red to compare with average seasonal melting shown by the blue line.
By Summit Voice
FRISCO — A heatwave in Greenland culminated last week in the highest temperature recorded on the Arctic island since record-keeping started in 1958.
The official weather station at Maniitsoq/Sugar Loaf in southeastern Greenland reported a July 30 reading of 25.9 degrees Celsius (78.6 degrees Fahrenheit), breaking the old Greenland record of 25.5 degrees, set in 1990 in the same area of Greenland.
The Danish Meteorological Institute confirmed the record temperature in a press release. According to the weather experts, the regional heatwave resulted from a strong high pressure system over Greenland combined with a low pressure system over Baffin Island, leading to a flow of warm, dry air from the southeast.
The Danish meteorologists also said that reflected sunlight may also have been a factor in the reading, which has yet to be officially confirmed as the all-time high temperature record. Continue reading
Filed under: climate and weather, Environment, global warming, Greenland | Tagged: climate change, Danish Meteorological Institute, Environment, extreme weather, global warming, greenland, Greenland ice sheet | 2 Comments »
Posted on July 20, 2013 by Bob Berwyn
Meltwater pools on the surface of the Sermeq Avannarleq Glacier, in a region about 10 miles from the ice sheet margin in Southwest Greenland. Photo courtesy William Colgan/CIRES.
Findings suggest sea level calculations may need to be adjusted
By Summit Voice
*Adapted from a NASA press release
FRISCO — Scientists are keeping close watch on the behavior of the Greenland ice sheet as they try and calculate how fast the ice will melt as the planet continues to warm. The stakes are high — acceleration of the meltdown will start to raise sea levels around the world at an increasing pace, so the speed-up of glaciers flowing into the sea have garnered plenty of attention.
And new satellite measurements suggest that some of Greenland’s giant glaciers are also moving up to 1.5 faster then they were just 10 years ago, possibly lubricated by surface meltwater draining through cracks and warming the ice from the inside.
“Through satellite observations, we determined that an inland region of the Sermeq Avannarleq Glacier, 40 to 60 miles from the coast, is flowing about 1.5 times faster than it was about a decade ago,” said Thomas Phillips, lead author of the new paper and a research associate at the time of the study with the Cooperative Institute for Research in Environmental Sciences at the University of Colorado, Boulder. Continue reading
Filed under: Arctic, climate and weather, Environment, global warming | Tagged: CIRES, climate, Cooperative Institute for Research in Environmental Sciences, global warming, Greenland ice sheet, sea level rise | Leave a comment »
Posted on July 16, 2013 by Bob Berwyn
Iceberg calving to be less of a factor as glaciers retreat
By Summit Voice
FRISCO — Greenland’s melting ice cap will continue to contribute to sea level rise, but iceberg calving will become less of a factor as glaciers retreat inland. Instead, surface melting and runoff will account for more than 80 percent of ice cap’s contribution to sea level rise, according to new research from the Vrije Universiteit Brussel.
Changes in its total mass are governed by two main processes — fluctuations in melting and snowfall on its surface, and changes to the number of icebergs released from a large number of outlet glaciers into the ocean. The ice loss from the ice sheet has been increasing during the last decade, with half of it attributed to changes in surface conditions with the remainder due to increased iceberg calving. Continue reading
Filed under: Arctic, climate and weather, Environment, global warming | Tagged: British Antarctic Survey, climate, Environment, global warming, greenland, Greenland ice sheet, ice2sea, sea level rise, Vrije Universiteit Brussel | 1 Comment »
Posted on July 14, 2013 by Bob Berwyn
Long-term trends still unclear
Ice floes melting on a warm spring day in the Antarctic Sound. Bob Berwyn photo.
By Summit Voice
FRISCO — Ice mass loss from both the Greenland Ice Sheet and Antarctica have doubled since accurate satellite-based gravity measurements started nine years ago, but it’s still not clear whether the melting will continue to accelerate at the same rate.
For now, the period of record is still too short to say, according to a new report published online this week in Nature Geosciences.
The research team was led by Bert Wouters, with the University of Bristol and included scientists with the GFZ German Research Centre for Geosciences.
The study concludes that predictions of the contribution of both ice shields to sea level rise through 2100 may be off by as much as 35 centimeters (about 13.8 inches) in either direction. Continue reading
Filed under: Antarctica, Arctic, climate and weather, Environment, global warming | Tagged: Antarctica, climate change, global warming, Gravity Recovery and Climate Experiment, greenland, Greenland ice sheet, sea level rise | Leave a comment »
Posted on June 30, 2013 by Bob Berwyn
Scientists measure profound changes in the Arctic climate system
By Summit Voice
SUMMIT COUNTY — The mighty Greenland ice sheet isn’t likely to melt down completely any time soon, but looking farther ahead, scientists say new research shows a significant and accelerating warming trend over the ice cap.
The long-term concern, of course, is sea level. When Greenland’s ice starts to melt quickly, it would speed up the sea level rise that’s already under way, with potentially devastating impacts for low-lying coastal areas. Scientists tracking the ice cap are posting their findings on the new Greenland Today website. Continue reading
Filed under: climate and weather, Environment, global warming | Tagged: CIRES, climate change, Dan McGrath, global warming, Greenland ice sheet, Greenland surface melting, University Colorado Boulder | 2 Comments »
Posted on June 18, 2013 by Bob Berwyn
July 2012 melt event far surpassed previous record
In the images above, areas classified as “probable melt” (light pink) correspond to sites where at least one satellite detected surface melting. Areas classified as “melt” (dark pink) correspond to sites where two or three satellites detected melting.
By Summit Voice
SUMMIT COUNTY — Along with an unusual constellation of low clouds, changes the jet stream were also a factor in last summer’s exceptional surface melt of the Greenland Ice Sheet, according to a research team led by the University of Sheffield’s geography professor Edward Hanna.
A NOAA study published in March indicated that a lingering layer of thin, low clouds helped intensify atmospheric conditions leading to the meltdown.
Hanna and his colleagues used a computer model simulation (called SnowModel) and satellite data to confirm that last summer’s meltdown was unprecedented in the past 50 years. About 90 percent of the ice-sheet surface melted July 11, far surpassing the previous known surface melt extent record of 52 percent in 2010. Continue reading
Filed under: climate and weather, Environment, global warming | Tagged: climate change, global warming, Greenland ice sheet, Intergovernmental Panel on Climate Change, North Atlantic Oscillation, Sheffield University | 1 Comment »