Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study shows snowfall hasn't increased over Antarctica in last 50 years

14.08.2006
An international effort to determine the variability of recent snowfall over Antarctica shows that there has been no real increase in precipitation over the southernmost continent in the last half-century.

The results are important since most accepted computer models assessing global climate change call for an increase in Antarctic precipitation as atmospheric temperatures rise.

The findings also suggest that the slow-but-steady rise in global sea levels isn't being slowed by a thickening of Antarctica 's massive ice sheets, as some climate-change critics have argued.

The conclusions were part of a paper published today in the latest issue of the journal Science. Sixteen researchers from nine institutions in seven countries took part in the study.

Andrew Monaghan, a research associate and meteorologist with Ohio State University's Byrd Polar Research Center and lead author on the paper, wrote that “there were no statistically significant trends in snowfall accumulation over the past five decades, including recent years for which global mean temperatures have been warmest.”

The study looked at both the West Antarctic Ice Sheet (WAIS), a marine ice sheet with a base below sea level, and the much thicker East Antarctic Ice Sheet (EAIS) that sits atop dry land. In recent years, large volumes of ice along the coast of the WAIS have melted at a rate previously unseen. Some observers have blamed global warming for this and for the increased calving of icebergs along the continent's margin.

The researchers wanted to assemble a half-century-long record of snowfall back to the International Geophysical Year, or IGY. Work during the IGY began the first real modern study of the Antarctic continent and substantive research has continued there ever since.

The research team coupled data from existing ice cores in the region, snow pits and networks of snow stakes, and meteorological observations. To these they added numerous new ice core records obtained by the International Transantarctic Scientific Expedition (ITASE), a 12-nation research program begun in 1990 and tasked with reconstructing the continent's climate history.

Lastly, the researchers relied on snowfall data from the European Centre for Medium-Range Weather Forecasts 40-Year Reanalysis (ERA-40), a project that uses a popular weather forecast model to re-evaluate global weather in recent years.

They were able to use the ERA-40 data to fill in the gaps between the ice core records. Since ERA-40 covers the entire continent, it increased the researchers' confidence in their conclusions.

“We're certain that our results are representative of the entire Antarctic continent and that the trends we do see are correct,” Monaghan said.

When they were finished, they had generated the most precise record of Antarctic snowfall yet, and doubled its length by 25 years. The reconstruction provided a picture of precipitation on both an annual and decadal scale that showed wide variations across the continent.

“This approach is quite a bit more reliable than a global climate model,” Monaghan said, adding that this method gives them snapshots of the Antarctic snowfall changes on a grid, something that wasn't possible with other methods.

Monaghan and his colleagues are cautious about their findings. They point to the short 50-year length of the record as a limitation of the study and long for at least a century of data before they can give a definitive answer about precipitation trends over Antarctica .

“The year-to-year and decadal variability of the snowfall is so large that it makes it nearly impossible to distinguish trends that might be related to climate change from even a 50-year record”, says Monaghan.

“This means that new, highly accurate satellite measurements of the amount of Antarctic ice must continue for several decades to determine whether Antarctica is gaining or losing water to the ocean.”

But as to whether warming in the atmosphere over the Antarctic and the surrounding oceans has brought more precipitation to balance the ice lost from edges of the continent during that latter part of the 20th Century, Monaghan points to the conclusion “that global sea level has not been mitigated by recently increased Antarctic snowfall as expected.”

The key issues now are how snowfall will change as the atmosphere continues to warm and whether climate model predictions of increased snowfall can be trusted, he said.

Other Ohio State researchers on the National Science Foundation-funded project included David Bromwich, professor of atmospheric sciences in the Department of Geography; and graduate student Ryan Fogt; Sheng-Hung Wang, a research associate with the Byrd Center; and Cornelius van der Veen, a Byrd Center glaciologist. Additional researchers from Russia, Italy, Australia, Norway, Germany and China were also co-authors on the paper.

Andrew Monaghan | EurekAlert!
Further information:
http://www.osu.edu

More articles from Studies and Analyses:

nachricht Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung

nachricht Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Researchers devise microreactor to study formation of methane hydrate

23.08.2017 | Materials Sciences

ShAPEing the future of magnesium car parts

23.08.2017 | Automotive Engineering

New insights into the world of trypanosomes

23.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>