Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study finds link between 2015 melting Greenland ice, faster Arctic warming

10.06.2016

A new study provides the first evidence that links melting ice in Greenland to a phenomenon known as Arctic amplification--faster warming of the Arctic compared to the rest of the Northern Hemisphere as sea ice disappears.

The findings show that the predicted effects of Arctic amplification, as described in previous studies, occurred over northern Greenland during summer 2015, including a northern swing of the jet stream that reached latitudes never before recorded in Greenland at that time of year.


Researchers including the University of Georgia's Thomas Mote measure meltwater runoff from the ice sheet margin in Greenland during summer 2013.

Courtesy of Thomas Mote/University of Georgia

The study, published today in Nature Communications, included researchers from University of Georgia, Columbia University, University of Liege, City College of New York, University of Leeds and the University of Sheffield.

The Greenland ice sheet, Earth's second largest after Antarctica, holds enough ice that if it were to melt entirely, it would raise average global sea level by about 7 meters, or almost 23 feet. Learning more about the drivers of melting is essential to discerning how much sea level will rise and by how much in the future and how Greenland's freshwater runoff will affect ocean circulation and ecology.

"During the past two decades, we have seen increasing melt from the Greenland ice sheet, culminating in a very large melt event in the summer of 2012," said study co-author Thomas Mote, a University of Georgia professor in the department of geography.

"Last year was unique in the extensive melting that occurred on the northern reaches of the ice sheet, an area that usually has rather modest melt compared to southern Greenland. We identified an unusual configuration of the jet stream toward northern Greenland that led to this melt pattern."

Rising global temperatures are melting Arctic sea ice, leaving dark open water that absorbs more solar radiation and causes faster warming in the Arctic. While Arctic amplification is well documented, its effects on the atmosphere are still debated. One theory among scientists is that the shrinking temperature difference between the Arctic and the temperate zone will lead to a slowing of the jet stream. Normally, when the jet stream circles the northern latitudes, the frigid polar air is separated from warmer air in the south. Slower winds, however, could create wilder swings that would allow warm, humid air to penetrate farther north.

"The Greenland ice sheet is one of the most important contributors to sea level rise since 2000," Mote said. "Moreover, some recent work has shown how meltwater runoff can affect ocean productivity and circulation in southern Greenland. However, we don't yet have a good understanding of how increased melt in the north might affect surrounding oceans and the dynamics of the ice sheet."

Northwest Greenland's summer melt started last June when a high-pressure ridge squeezed off from the jet stream and moved westward over Greenland and hovered over the Arctic Ocean, the study shows. Clear skies and warmer weather in northern Greenland from this high-pressure system resulted in record setting surface temperature and meltwater runoff in the northwest. With less summer snow falling and melting underway, northern Greenland's reflectivity also decreased and the water absorbed more heat from the sun, further increasing melting.

Northern Greenland's wind patterns also changed from the usual west to east direction to east to west. Only two other years on record show east to west wind averages in July and both were slower. Further, the jet stream's northernmost ridge swung nearly 2 degrees farther north than the previous July record, set in 2009.

The same atmospheric pattern had a different impact on southern Greenland, where new melting records have been set over the past decade. The south saw more snow during summer 2015 and less melting than previous years.

"How much and where Greenland melts can change depends on how things change elsewhere on Earth," said the study's lead author Marco Tedesco, a research professor at Columbia University's Lamont-Doherty Earth Observatory and adjunct scientist at NASA Goddard Institute for Space Studies. "If loss of sea ice is driving changes in the jet stream, the jet stream is changing Greenland, and this, in turn, has an impact on the Arctic system as well as the climate. It's a system, it is strongly interconnected, and we have to approach it as such."

The authors don't fully confirm Arctic amplification as the cause of the warming, but say the results of their study fit the description of possible effects as predicted by other researchers. Whether the patterns seen in 2015 will continue in the future is uncertain. This spring, Arctic sea ice set another record low for its maximum extent for the year.

"Greenland also experienced early season melt in early April of this year comparable to April 2012. Record-setting melt occurred later that summer, but it is too early to tell whether the same will hold true in 2016," Mote said.

###

Additional co-authors are Xavier Fettweis of University of Liege; Jeyavinoth Jeyaratnam, James Booth and Rajashree Datta of City College of New York; and Kate Briggs of University of Leeds.

The study, "Arctic cut-off high drives the poleward shift of a new Greenland melting record," was supported by funding from NASA's Interdisciplinary Data Science Program, NASA's Cryosphere Program and the National Science Foundation and is available at http://www.nature.com/ncomms/2016/160609/ncomms11723/full/ncomms11723.html.

Media Contact

Stephanie Schupska
schupska@uga.edu
706-542-6927

 @universityofga

http://www.uga.edu 

Stephanie Schupska | EurekAlert!

More articles from Earth Sciences:

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

nachricht Modeling magma to find copper
13.01.2017 | Université de Genève

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

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

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>