Featured Research

from universities, journals, and other organizations

Scientists investigate release of bromine in polar regions

Date:
April 26, 2013
Source:
Heidelberg, Universität
Summary:
Researchers have employed a novel measurement device for new studies in Alaska.

American research aircraft from Purdue University with measurement devices from the Institute of Environmental Physics in flights over Alaska in spring 2012. A part of the instruments is installed below the aircraft. From there, the collected light signals are transmitted to the other instruments inside the plane. Prof. Dr. Paul B. Shepson of Purdue University piloted the aircraft, with a colleague controlling the instruments.
Credit: Stephan General

The chemical element bromine, whose compounds contribute significantly to the depletion of ozone in the lower atmosphere, is also released in polar regions to a great extent from snow on land. This is the result reached by an international research team of scientists from the Institute of Environmental Physics of Heidelberg University and colleagues from the USA, who performed measurements and sampling together in Alaska. Until now, science has assumed that sea ice was the sole source of bromine emissions. A novel spectroscopic measurement device, developed in Heidelberg, was used aboard an American research aircraft for this study.

The results of this research have now been published in Nature Geoscience.

Ozone plays a key role not only in the stratosphere, but also on the ground. While at ground level it is not particularly relevant for the protection from UV radiation, it is for the self-cleaning of the atmosphere and removal of contaminants. In the 1990s Heidelberg researchers working with Prof. Dr. Ulrich Platt had already discovered that the extensive ozone depletion in the atmosphere close to the ground in the Arctic and Antarctic was due to a reaction of bromine with ozone, producing bromine oxide. This bromine is released in autocatalytic processes. During the polar spring, the resulting bromine oxide clouds can spread over several thousand square kilometres. "It is by far the largest release of bromine on our planet," says Prof. Platt of the Institute of Environmental Physics at Heidelberg University. The precise processes involved are quite complex and are still a topic of current research.

Now the investigations in Alaska by the international team of scientists have yielded new information on the release of bromine from ice and snow. The researchers studied a variety of samples taken on site. It appears that the bromine-release processes are correlated to daylight, and thus involve photochemical reactions. Most importantly, however, the team was able to prove that the bromine emissions depended heavily on the pH value of the snow or ice sample. "The more acidic the sample, the more bromine was released. This led to the surprising result that snow on land, which is typically acidic, releases more bromine than alkaline sea ice, even though sea ice clearly contains more bromine," explains Dr. Denis Pöhler, a member of Prof. Platt's team.

The scientists from Heidelberg University confirmed these findings particularly through simultaneous observations from the aircraft. The instrument, which was developed as part of a project funded by the German Research Foundation at the Institute of Environmental Physics, measures the sunlight reflected and scattered on the surface of the snow and in the atmosphere. Bromine oxide absorbs some of the sunlight. Based on the amount of absorption, the Heidelberg scientists were able to determine the bromine concentration and its vertical distribution up to several kilometres altitude. They also obtained data on its horizontal distribution. "This kind of comprehensive data allows us to precisely find the sources of bromine release in the Arctic," stresses Dr. Pöhler.

The studies were conducted as part of the "Bromine, Ozone and Mercury Experiment" (BROMEX). Collaborators included researchers from Purdue University in West Lafayette/Indiana, the Cold Regions Research and Engineering Laboratory in Fort Wainwright/Alaska, the University of Alaska Fairbanks and the Georgia Institute of Technology in Atlanta. The instrument developed in Heidelberg will be used aboard the new German HALO research aircraft to measure not only bromine oxide, but also other compounds of significance for the atmosphere, such as nitrogen dioxide and sulphur dioxide.


Story Source:

The above story is based on materials provided by Heidelberg, Universität. Note: Materials may be edited for content and length.


Journal Reference:

  1. Kerri A. Pratt, Kyle D. Custard, Paul B. Shepson, Thomas A. Douglas, Denis Pöhler, Stephan General, Johannes Zielcke, William R. Simpson, Ulrich Platt, David J. Tanner, L. Gregory Huey, Mark Carlsen, Brian H. Stirm. Photochemical production of molecular bromine in Arctic surface snowpacks. Nature Geoscience, 2013; DOI: 10.1038/ngeo1779

Cite This Page:

Heidelberg, Universität. "Scientists investigate release of bromine in polar regions." ScienceDaily. ScienceDaily, 26 April 2013. <www.sciencedaily.com/releases/2013/04/130426114858.htm>.
Heidelberg, Universität. (2013, April 26). Scientists investigate release of bromine in polar regions. ScienceDaily. Retrieved August 30, 2014 from www.sciencedaily.com/releases/2013/04/130426114858.htm
Heidelberg, Universität. "Scientists investigate release of bromine in polar regions." ScienceDaily. www.sciencedaily.com/releases/2013/04/130426114858.htm (accessed August 30, 2014).

Share This




More Earth & Climate News

Saturday, August 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Volcano Erupts on Papua New Guinea

Raw: Volcano Erupts on Papua New Guinea

AP (Aug. 29, 2014) — Several communities were evacuated and some international flights were diverted on Friday after one of the most active volcanos in the region erupts. (Aug. 29) Video provided by AP
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) — State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Scientists Have Figured Out Why Rocks Move In Death Valley

Scientists Have Figured Out Why Rocks Move In Death Valley

Newsy (Aug. 28, 2014) — The mystery of the moving rocks in Death Valley, California, has finally been solved. Scientists are pointing to a combo of water, ice and wind. Video provided by Newsy
Powered by NewsLook.com
Big Waves, Minor Flooding from Hurricane

Big Waves, Minor Flooding from Hurricane

AP (Aug. 27, 2014) — Thundering surf spawned by Hurricane Marie pounded the Southern California coast Wednesday, causing minor flooding in a low-lying beach town. High surf warnings were posted for Los Angeles County south through Orange County. (Aug. 27) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins