IEDA
Project Information
Deciphering Changes in Atmospheric Nitrous Oxide Concentration During the Last Ice Age Using the Intramolecular Site-Preference of Nitrogen Isotopes
Short Title:
Atmospheric Nitrous Oxide Concentration During the Last Ice Age
Start Date:
2019-08-15
End Date:
2024-01-31
Description/Abstract
The objective of this project was to understand why the nitrous oxide (N2O) content of the atmosphere was lower during the last ice age (about 20,000-100,000 years ago) than in the subsequent warm period (10,000 years ago to present) and why it fluctuated during climate changes within the ice age. Nitrous oxide is a greenhouse gas that contributes to modern global warming. It is thought that modern warming will in turn cause increases in natural sources of nitrous oxide from bacteria in soils and the ocean, creating a "positive feedback." However, the amount these sources will increase is uncertain because the different ways that nitrous oxide are produced, and how sensitive they are to warmer climate, are not well known. This project measured a unique property of the nitrous oxide molecule in very large ancient air samples from a glacier in Antarctica. This method can distinguish between different microbial processes that produce nitrous oxide but it has not been applied yet to the time periods in question. The data provide information about how natural climate changes affect nitrous oxide production. This project developed two records of the intramolecular site preference of Nitrogen-15 in N2O. One record spans the last deglaciation (10,000-21,000 years ago) when atmospheric N2O concentration rose by 30 percent, and the other record spans millennial-scale climate changes during the last ice age when N2O varied by smaller amounts (Heinrich Stadial 4 and Dansgaard Oeschger 8, 35,000-41,000 years ago). The records will be used to understand what changes in the nitrogen cycle caused atmospheric N2O concentration to vary and what mechanisms link the N2O emissions to climate change. This work also allowed exploration of an isotopic tracer for in situ production of N2O that contaminates the atmospheric signal in particularly dusty ice.
Personnel
Person Role
Brook, Edward Investigator and contact
Funding
Antarctic Earth Sciences Award # 1903681
Antarctic Glaciology Award # 1903681
AMD - DIF Record(s)
USAP-1903681_1
Deployment
Deployment Type
Taylor Glacier field camp
Data Management Plan
None in the Database
Product Level:
1 (processed data)

This project has been viewed 12 times since May 2019 (based on unique date-IP combinations)