Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Clearest evidence yet of polar ice losses

30.11.2012
After two decades of satellite observations, an international team of experts brought together by ESA and NASA has produced the most accurate assessment of ice losses from Antarctica and Greenland to date. This study finds that the combined rate of ice sheet melting is increasing.

The new research shows that melting of the Antarctic and Greenland ice sheets has added 11.1 mm to global sea levels since 1992. This amounts to about 20% of all sea-level rise over the survey period.

About two thirds of the ice loss was from Greenland, and the remainder was from Antarctica.

Although the ice sheet losses fall within the range reported by the Intergovernmental Panel on Climate Change in 2007, the spread of the estimate at that time was so broad that it was not clear whether Antarctica was growing or shrinking.

The new estimates are a vast improvement – more than twice as accurate – thanks to the inclusion of more satellite data, and confirm that both Antarctica and Greenland are losing ice.

The study also shows that the combined rate of ice sheet melting has increased over time and, altogether, Greenland and Antarctica are now losing more than three times as much ice, equivalent to 0.95 mm of sea-level rise per year, as they were in the 1990s, equivalent to 0.27 mm of sea level rise per year.

The 47 experts combined observations from 10 different satellite missions to reconcile the differences between dozens of earlier ice sheet studies and produce the first consistent measurement of polar ice sheet changes.

Earth observation satellites are key to monitoring the polar ice because they carry instruments that measure changes in the thickness of the ice sheets, fluctuations in the speed of the outlet glaciers and even small changes in Earth’s gravity field caused by melting ice.

As outlined in the paper ‘A Reconciled Estimate of Ice Sheet Mass Balance’ published today in Science, the researchers carefully matched time periods and survey areas, and combined measurements from European, Canadian, American and Japanese satellites.

The measurement were acquired by instruments such as the radar altimeters and synthetic aperture radars flown on ESA’s ERS-1, ERS-2 and Envisat missions from 1991.

“The success of this venture is due to the cooperation of the international scientific community, and to the provision of precise satellite sensors by our space agencies,” said Professor Andrew Shepherd from the University of Leeds and one of the leaders of the study.

“Without these efforts, we would not be in a position to tell people with confidence how Earth’s ice sheets have changed, and to end the uncertainty that has existed for many years.”

The study also found variations in the pace of ice sheet change in Antarctica and Greenland.

“The rate of ice loss from Greenland has increased almost five-fold since the mid-1990s.

“In contrast, while the regional changes in Antarctic ice over time are sometimes quite striking, the overall balance has remained fairly constant – at least within the certainty of the satellite measurements we have to hand,” said co-leader of the study Dr Erik Ivins from NASA’s Jet Propulsion Laboratory.

The Ice Sheet Mass Balance Inter-comparison Exercise is a collaboration between 47 researchers from 26 laboratories, supported by ESA and NASA.

Europe’s Global Monitoring for Environment and Security programme will continue to monitor changes in the polar ice sheets during the coming decades, with the SAR and radar altimeter sensors on the Sentinel-1 and Sentinel-3 satellite series, scheduled to be launched from 2013 onwards.

Robert Meisner | EurekAlert!
Further information:
http://www.esa.int

More articles from Earth Sciences:

nachricht New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg

nachricht Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>