Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Flat Antarctica – Land height could help explain why Antarctica is warming slower than the Arctic

18.05.2017

Temperatures in the Arctic are increasing twice as fast as in the rest of the globe, while the Antarctic is warming at a much slower rate. A new study published in Earth System Dynamics, a journal of the European Geosciences Union, shows that land height could be a “game changer” when it comes to explaining why temperatures are rising at such different rates in the two regions.

Climate models and past-climate studies show that, as the Earth warms in response to an increase in greenhouse gases in the atmosphere, temperatures rise faster at the poles than in other parts of the planet. This is known as polar amplification. But this amplified warming is not the same at both poles.


Antarctica is the highest continent on Earth, with an average elevation of about 2,500m. It is peppered with many mountains and ridges.

Tarun Luthra, distributed via imaggeo.egu.eu

“On average, warming for the entire Antarctic continent has been much slower than Arctic warming so far. Moreover, climate models suggest that, by the end of this century, Antarctica will have warmed less compared to the Arctic,” says Marc Salzmann, a researcher at the Institute for Meteorology, University of Leipzig in Germany.

A possible cause for the accelerated Arctic warming is the melting of the region’s sea ice, which reduces the icy, bright area that can reflect sunlight back out into space, resulting in more solar radiation being absorbed by the dark Arctic waters. Scientists believe this is an important contribution to warming in the region, but it’s not the only one.

Changes to the transport of heat by the Earth’s atmosphere and oceans to the poles have also been suggested as a possible contributor to the steep rise in Arctic temperatures. In addition, the cold temperatures and the way air is mixed close to the surface at the poles mean that the surface has to warm more to radiate additional heat back to space. These effects may not only lead to stronger warming at the north of our planet, but also at the south polar region.

“I wondered why some of the reasons to explain Arctic warming have not yet caused strongly amplified warming in all of Antarctica as well,” says Salzmann, the author of the Earth System Dynamics study. There had to be other factors at play.

“I thought that land height could be a game changer that might help explain why the Arctic has thus far warmed faster than Antarctica,” he says.

With an average elevation of about 2,500 m, Antarctica is the highest continent on Earth, much due to a thick layer of ice covering the bedrock. The continent also has high mountains, such as Mount Vinson, which rises almost 4,900 m above sea level.

To test his idea, Salzmann used a computer model of the Earth system to find out how the climate would react to a doubling of the atmospheric carbon-dioxide concentration. He also ran the same experiment in a flat-Antarctica world, where he artificially decreased the land height over the entire southern continent to one metre, a value similar to the surface height in the Arctic. This allowed him to compare how differently the Earth would react to an increase in greenhouse-gas concentrations in the atmosphere if Antarctica was assumed flat.

The experiments showed that, if Antarctica’s land height is reduced, temperatures in the region respond more strongly to a rise in the concentration of greenhouse gases over the continent. This contributes to an increase in Antarctic warming, which reduces the difference in polar amplification between the Arctic and the Antarctic.

The most significant factor, however, was a change in the way heat is transported in the atmosphere from the equator to the poles in the flat Antarctica world compared to the reference model. “Assuming a flat Antarctica allows for more transport of warm air from lower latitudes,” Salzmann explains. “This is consistent with the existing view that when the altitude of the ice is lowered, it becomes more prone to melting,” Salzmann explains.

In the long term, this could contribute to accelerate Antarctic warming in the real world. As the region warms due to increased greenhouse-gas emissions, ice melts, reducing Antarctica’s elevation over centuries or thousands of years. This, in turn, would contribute to even more warming.

# # #

Please mention the name of the publication (Earth System Dynamics) if reporting on this story and, if reporting online, include a link to the paper (http://www.earth-syst-dynam.net/8/323/2017/ [link active after embargo lifts; embargoed pre-print available at https://www.egu.eu/news/333/flat-antarctica-land-height-could-help-explain-why-a...]) or to the journal website (http://www.earth-system-dynamics.net).

MORE INFORMATION
This research, by Marc Salzmann (Institute for Meteorology, Universität Leipzig, Germany), is presented in the paper ‘The polar amplification asymmetry: Role of antarctic surface height’ to appear in the EGU open access journal Earth System Dynamics on 18 May 2017.

The scientific article is available online, free of charge, from the publication date onwards, at http://www.earth-syst-dynam.net/8/323/2017/ (this URL will redirect to the final, peer-reviewed paper only after the study is published). An embargoed pre-print version of the final paper is available for download at https://www.egu.eu/news/333/flat-antarctica-land-height-could-help-explain-why-a... (scroll down to the Media section).

Citation: Salzmann, M.: The polar amplification asymmetry: Role of antarctic surface height, Earth Syst. Dynam., doi:10.5194/esd-8-323-2017, 2017

The European Geosciences Union (www.egu.eu) is Europe’s premier geosciences union, dedicated to the pursuit of excellence in the Earth, planetary, and space sciences for the benefit of humanity, worldwide. It is a non-profit interdisciplinary learned association of scientists founded in 2002. The EGU has a current portfolio of 17 diverse scientific journals, which use an innovative open access format, and organises a number of topical meetings, and education and outreach activities. Its annual General Assembly is the largest and most prominent European geosciences event, attracting over 13,000 scientists from all over the world. The meeting’s sessions cover a wide range of topics, including volcanology, planetary exploration, the Earth’s internal structure and atmosphere, climate, energy, and resources. The EGU 2017 General Assembly is taking place in Vienna, Austria, from 23 to 28 April 2017. For information about meeting and press registration, please check http://media.egu.eu, or follow the EGU on Twitter (@EuroGeosciences) and Facebook (EuropeanGeosciencesUnion).

If you wish to receive our press releases via email, please use the Press Release Subscription Form at http://www.egu.eu/news/subscribe/. Subscribed journalists and other members of the media receive EGU press releases under embargo (if applicable) at least 24 hours in advance of public dissemination.

Earth System Dynamics (ESD, http://www.earth-system-dynamics.net/) is an international scientific journal dedicated to the publication and public discussion of studies that take an interdisciplinary perspective of the functioning of the whole Earth system and global change. The overall behaviour of the Earth system is strongly shaped by the interactions among its various component systems, such as the atmosphere, cryosphere, hydrosphere, oceans, pedosphere, lithosphere, and the inner Earth, but also by life and human activity. ESD solicits contributions that investigate these various interactions and the underlying mechanisms, ways how these can be conceptualised, modelled, and quantified, predictions of the overall system behaviour to global changes, and the impacts for its habitability, humanity, and future Earth system management by human decision making.

LINKS
Scientific paper: http://www.earth-syst-dynam.net/8/323/2017/ (the link will be active after the study is published on 18 May, 2pm; embargoed pre-print available at https://www.egu.eu/news/333/flat-antarctica-land-height-could-help-explain-why-a...)
Journal – Earth System Dynamics: http://www.earth-system-dynamics.net/

CONTACTS
Scientist

Marc Salzmann
Institute for Meteorology
University of Leipzig, Germany
Phone +49 341/97-32932
Email: marc.salzmann@uni-leipzig.de

Press officers

Bárbara Ferreira
EGU Media and Communications Manager
Munich, Germany
Phone: +49-89-2180-6703
Email: media@egu.eu
Twitter: @EuroGeosciences

Universität Leipzig
University Communications
Phone: +49 341 97-35021
Mobile: +49 170 4548700
Email: presse@uni-leipzig.de
Web: www.uni-leipzig.de/kommunikation

Weitere Informationen:

http://www.egu.eu/news/333/flat-antarctica-land-height-could-help-explain-why-an... (HTML version of this release, including the scientific study, a video and photos)

Dr. Bárbara Ferreira | idw - Informationsdienst Wissenschaft

More articles from Earth Sciences:

nachricht Geophysicists and atmospheric scientists partner to track typhoons' seismic footprints
16.02.2018 | Princeton University

nachricht NASA finds strongest storms in weakening Tropical Cyclone Sanba
15.02.2018 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

Im Focus: Autonomous 3D scanner supports individual manufacturing processes

Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).

Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Fingerprints of quantum entanglement

16.02.2018 | Information Technology

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers

16.02.2018 | Health and Medicine

Hubble sees Neptune's mysterious shrinking storm

16.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>