Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NASA researcher finds days of snow melting on the rise in Greenland

31.05.2007
In 2006, Greenland experienced more days of melting snow and at higher altitudes than average over the past 18 years, according to a new NASA-funded project using satellite observations.

Daily satellite observations have shown snow melting on Greenland’s ice sheet over an increased number of days. The resulting data help scientists understand better the speed of glacier flow, how much water will pour from the ice sheet into the surrounding ocean and how much of the sun’s radiation will reflect back into the atmosphere.

"We now have the ability to monitor melting snow on Greenland’s ice sheet on a daily basis using sensors on satellites measuring the electromagnetic signal naturally emitted by the ice sheet," said Marco Tedesco, research scientist at the Joint Center for Earth Systems Technology cooperatively managed by NASA’s Goddard Space Flight Center, Greenbelt, Md., and the University of Maryland at Baltimore County, Baltimore.

"The sensors detected that snowmelt occurred more than 10 days longer than the average over certain areas of Greenland in 2006," said Tedesco, who is lead author of the study, which appears in the May 29 issue of the American Geophysical Union's Eos.

Tedesco applied a new method for detecting melting snow to data from the Special Sensor Microwave Imaging radiometer (SSM/I) flying aboard the Defense Meteorological Satellite Program spacecraft. The sensor can see through clouds and does not require sunlight to make measurements, providing researchers with multiple daily observations. Tedesco has updated the results annually since 1988, which has enabled him to analyze trends in the duration of snowmelt and extent over specific areas of Greenland.

To understand why these trends are important to track, Tedesco explained one of the consequences of melting snow. "Although wet and dry snow look similar at first glance, wet and re-frozen snow absorb more of the sun’s radiation, reflecting only 50-60 percent back into the atmosphere. Dry snow, on the other hand, reflects about 85 percent of the sun’s radiation," he said. "In other words, melting snow absorbs three to four times as much energy as dry snow, greatly affecting Earth’s energy budget."

The Earth’s energy budget refers to the balance between incoming sunlight and outgoing radiant energy.

Greenland's melting snow can have a major impact on the vast ice sheet and on sea level around the world. "The melting snow produces liquid water that will potentially influence sea levels," said Tedesco. "And some of the liquid water will drain into the glaciers through cracks and vertical passages, called moulins, reaching the bedrock below and lubricating the ice sheet."

Previous studies by NASA Goddard researchers Jay Zwally and Waleed Abdalati have also observed that the water from summer melting at the ice sheet's base can increase how fast the ice moves, causing it to contribute more rapidly to sea level than previously thought. This phenomenon, together with others recently observed, suggest that the ice might respond more quickly to a warming climate.

To estimate the overall impact on Greenland's snow, Tedesco's study calculated a "melt index," which is the number of melting days multiplied by the melting area. The 2006 data followed the increasing trend from 1988 to 2005. Areas along Greenland’s western, southeastern and northeastern coast witnessed the largest number of melt days in 2006.

"The International Polar Year’s focus on this part of the world gives us an ideal opportunity to combine research results on snowmelt from satellites as well as from climate models to better understand how melting is really affecting the mass balance of Greenland’s ice sheet. We need to link all of this data together to get a better view of this complex system."

Gretchen Cook-Anderson | EurekAlert!
Further information:
http://www.nasa.gov/centers/goddard/news/topstory/2007/snowmelt_greenland.html

More articles from Earth Sciences:

nachricht Early organic carbon got deep burial in mantle
25.04.2017 | Rice University

nachricht New atlas provides highest-resolution imagery of the Polar Regions seafloor
25.04.2017 | British Antarctic Survey

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Early organic carbon got deep burial in mantle

25.04.2017 | Earth Sciences

A room with a view - or how cultural differences matter in room size perception

25.04.2017 | Life Sciences

Warm winds: New insight into what weakens Antarctic ice shelves

25.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>