Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NASA Scientist Claims Warmer Ocean Waters Reducing Ice Worldwide

27.03.2006


Jakobshavn Glacier Retreat 2001-2003: Jakobshavn Isbrae holds the record as Greenland’s fastest moving glacier and major contributor to the mass balance of the continental ice sheet. Starting in late 2000, following a period of slowing down in the mid 1990s, the glacier showed significant acceleration and nearly doubled its discharge of ice. The following image from the Landsat satellite shows the retreat of Jakobshavn’s calving front from 2001 to 2003. Credit: NASA


Glaciers and ice sheets around the world have a big problem: warmer waters.

According to a NASA scientist, the pieces to a years-old scientific puzzle have come together to confirm warmer water temperatures are creeping into the Earth’s colder areas. Those warm waters are increasing melting and accelerating ice flow in polar areas.

This conclusion appears in an article by Robert Bindschadler, a glaciologist at NASA’s Goddard Space Flight Center in Greenbelt, Md. His article is in the March 24 issue of Science magazine.



Temperatures collected from ships and buoys showed a warming of all oceans. That increase began before satellite sensors detected temperature increases of sea surfaces. Most of the warming was limited to the oceans’ upper 1000 meters (.62 mile), except in the North Atlantic. In the cold North Atlantic waters, heat penetrated even deeper. This warming has increased the melting of sea ice in the North Atlantic. Overall ocean heat content changes are monitored by ocean altimetry missions like TOPEX and Jason-1 and the on site Argo buoy network floats that broadcast measurements to a satellite. These provide information on ocean temperatures.

It has another effect, however, which may potentially be of great significance to sea level rise, and that is that these warm waters are beginning to melt the underside of the floating fringes of the Greenland ice sheet, even at great depths, It is these fringes that have been holding back vast stores of ice locked up in the Greenland ice sheet, and as this ice has been melting, the glaciers have hastened their flow to the sea.

A recent assessment in the changes in speed and the amount of snow and ice around Greenland confirms a large melting of outflow glaciers and acceleration of ice flow. Three large glaciers, the Kangerdlugssuaq, Helheim and Jakobshavns Isbrae have been melting at a rapid rate over the past several years. Jakobshavns, the largest outlet glacier on Greenland’s east coast, has been annually thinning at 15 meters (49.2 feet) since 1997. The other two glaciers have also been thinning. Kangerdlugssuaq at 40 meters (131.2 feet) per year and Helheim at 25 meters per year (82.0 feet), which can’t be explained by normal melting. All of these glaciers have also been accelerating. This isn’t just happening in Greenland, scientists are seeing similar behavior in Antarctica as well.

"Deep outlet glaciers around both major ice sheets are accelerating and thinning means warm water has reached them," Bindschadler said. "I see no process to reverse this and expect increased ice sheet discharge to continue and probably to spread with the result being further accelerations to sea level rise."

"Understanding just how significant these rapid losses are to the overall ice sheet balance requires a comprehensive look at melt, accumulation and flow characteristics over the entire ice sheet," said Waleed Abdalati, head of the Cryospheric Sciences Branch at Goddard. "Various satellite and aircraft observations are providing this critical information and are shaping our understanding of Greenland’s behavior. The story is still unfolding, but the dramatic changes at the margins are quite striking."

The evidence is clear to Bindschadler that increased snowfall predicted in a warmer climate can’t possibly keep up.

While it is true that the piece is opinion, it fits previously disconnected pieces of the climate and ice puzzle together and attempts to draw conclusions. The conclusions cannot be verified without new measurements, and NASA is compiling them with satellites like ICESat. ICESat enables scientists to precisely measure changes in the elevation of ice and snow on glaciers and ice sheets as they respond to a changing climate.

In an effort to understand these changes, NASA continues to monitor sea surface temperatures; and, the behavior of glaciers and ice sheets around the world.

Bindschadler said as sea ice diminishes over time in the Arctic and parts of the Antarctic, warmer waters in polar areas will come closer to the surface. They will reach shallower tidewater glaciers, and increase melting at their bases triggering additional ice flow into the oceans. Over time, the warmer waters also will move northward along Greenland’s coasts initiating acceleration and thinning of additional glaciers, leading to additional sea level rise.

Rob Gutro | EurekAlert!
Further information:
http://www.nasa.gov
http://www.nasa.gov/centers/goddard/news/topstory/2006/ice_puzzle.html

More articles from Earth Sciences:

nachricht New research calculates capacity of North American forests to sequester carbon
16.07.2018 | University of California - Santa Cruz

nachricht Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Microscopic trampoline may help create networks of quantum computers

17.07.2018 | Information Technology

In borophene, boundaries are no barrier

17.07.2018 | Materials Sciences

The role of Sodium for the Enhancement of Solar Cells

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>