Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nitrous oxide record sheds light on glacial carbon dioxide

15.08.2003


A 106,000-year-long record of nitrous oxide concentrations and a shorter record of nitrogen and oxygen isotopes show that both marine and terrestrial nitrous oxide production increased in unison and effectively by the same proportional amount during the end of the last glacial period, according to Penn State researchers.



Equal terrestrial and marine production of nitrous oxide also suggest that increased storage of carbon in the oceans was not the cause of low atmospheric carbon dioxide during ancient glacial periods, the researchers report in today’s (Aug. 15) issue of Science.

“Nitrous oxide is a greenhouse gas, but there is so little of it in the atmosphere, that it hardly contributes to climate change through changes in the radiation budget,” says Dr. Todd Sowers, research associate in geosciences. “Changes in nitrous oxide loading can, however, provide clues about systems that control carbon dioxide in the atmosphere.”


Sowers, working with Dr. Richard B. Alley, the Evan Pugh professor of geosciences, and Jennifer Jubenville, former graduate student, looked at nitrous oxide from the Greenland Ice Core Project II ice core to catalog atmospheric nitrous oxide concentrations through time.

“This is a new record of concentration variations back this far, only a small portion had been done before” says Sowers. “We found a 40 percent increase in the concentration of nitrous oxide in the atmosphere as the Earth warmed at the end of the last glacial period.”

The concentration data alone shows how much nitrous oxide was in the atmosphere at any particular time. It cannot, however, suggest how much of that gas came from the oceans or land. The researchers also looked at an ice core from the Taylor Dome, Antarctica, to create a 30,000-year history of the isotopic composition of the nitrogen and oxygen in the nitrous oxide.

Bacteria on land and in the oceans produce nitrous oxide in one of two ways. Ocean bacteria tend to create nitrous oxide that has more of the heavier isotopes of nitrogen and oxygen, while terrestrial bacteria tend to produce nitrous oxide with the lighter atoms. By looking at proportions of isotopes in the trapped gases, the researchers could determine how much was made on land and how much in the oceans.

“Before we had the isotope records, common wisdom suggested changes in terrestrial emission were probably the major player responsible for the observed concentration changes,” says Sowers. “Our isotope data, however, show that both oceanic and terrestrial emissions changed in roughly the same proportion throughout the last 30,000 years.”

Carbon dioxide in the atmosphere hits lows during glacial periods and some researchers have suggested that increased productivity in the glacial oceans could have removed carbon dioxide from the atmosphere. If the oceans behaved as they do today, then increased oceanic productivity during the glacial period would have produced elevated oceanic nitrous oxide production. However, if the relationship between terrestrial and marine nitrous oxide did not change, then this cannot be an explanation for the low levels of carbon dioxide in the atmosphere during glacial periods.

“When we thought terrestrial emissions were the dominant control on atmospheric nitrous oxide concentrations, then this hypothesis could have been true,” says Sowers. “Now that we know that the land and oceans contributed equally, we have to look for another explanation for the low carbon dioxide levels.”

A’ndrea Messer | Pennstate Un iversity
Further information:
http://live.psu.edu/story/3770

More articles from Earth Sciences:

nachricht Climate change weakens Walker circulation
20.10.2017 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen

nachricht Shallow soils promote savannas in South America
20.10.2017 | Senckenberg Forschungsinstitut und Naturmuseen

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

Metallic nanoparticles will help to determine the percentage of volatile compounds

20.10.2017 | Materials Sciences

Shallow soils promote savannas in South America

20.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>