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 Colorado River's connection with the ocean was a punctuated affair
16.11.2017 | University of Oregon

nachricht Researchers create largest, longest multiphysics earthquake simulation to date
14.11.2017 | Gauss Centre for Supercomputing

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>