Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Nitrous oxide record sheds light on glacial carbon dioxide


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:

More articles from Earth Sciences:

nachricht Wandering greenhouse gas
16.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Unique Insights into the Antarctic Ice Shelf System
14.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>