UNIVERSITY OF CALIFORNIA, SAN DIEGO
Grant: $700,302 - National Science Foundation - Jun. 19, 2009
25% voted satisfied - 75% voted not satisfied - 4 vote(s) cast
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Award Description: This award supports a project to develop a precise gas-based chronology for an archive of large-volume samples of the ancient atmosphere, which would enable ultra-trace gas measurements that are currently precluded by sample size limitations of ice cores. The intellectual merit of the proposed work is that it will provide a critical test of the 'clathrate hypothesis' that methane clathrates contributed to the two abrupt atmospheric methane concentration increases during the last deglaciation 15 and 11 kyr ago. This approach employs large volumes of ice (>1 ton) to measure carbon-14 on past atmospheric methane across the abrupt events. Carbon-14 is an ideal discriminator of fossil sources of methane to the atmosphere, because most methane sources (e.g., wetlands, termites, biomass burning) are rich in carbon-14, whereas clathrates and other fossil sources are devoid of carbon-14. The proposed work is a logical extension to Taylor Glacier, Antarctica, of an approach pioneered at the margin of the Greenland ice sheet over the past 7 years. The Greenland work found higher-than-expected carbon-14 values, likely due in part to contaminants stemming from the high impurity content of Greenland ice and the interaction of the ice with sediments from the glacier bed. The data also pointed to the possibility of a previously unknown process, in-situ cosmogenic production of carbon-14 methane (radiomethane) in the ice matrix. Antarctic ice in Taylor Glacier is orders of magnitude cleaner than the ice at the Greenland site, and is much colder and less stratigraphically disturbed, offering the potential for a clear resolution of this puzzle and a definitive test of the cosmogenic radiomethane hypothesis. Even if cosmogenic radiomethane in ice is found, it still may be possible to reconstruct atmospheric radiomethane with a correction enabled by a detailed understanding of the process, which will be sought by co-measuring carbon-14 in carbon monoxide and carbon dioxide. The broader impacts of the proposed work are that the clathrate test may shed light on the stability of the clathrate reservoir and its potential for climate feedbacks under human-induced warming. Development of Taylor Glacier as a 'horizontal ice core' would provide a community resource for other researchers. Education of one postdoc, one graduate student, and one undergraduate, would add to human resources. This award has field work in Antarctica.
Project Description: The expected major outcomes of this project include: 1) the hiring of one Graduate Student Researcher who will do his dissertation on gases trapped in the ice of Taylor Glacier, Antarctica over the next four years; 2) purchase of an ice core drill for $348,800 from a vendor located in Madison, WI (Ice Drilling Design and Operations, University of Wisconsin); and 3) scientific knowledge concerning the mechanism of past abrupt changes in Earth's climate, that may inform policy decisions No binding deliverables are committed to, as this is a research grant, but expected deliverables include two scientific publications, three presentations of results at scientific meetings such as the American Geophysical Union, and samples of scientific materials for further analysis (ancient air and ice that will be stored at the Scripps Institution of Oceanography). A chronology of the ice exposed in Taylor Glacier will be provided, for use by other researchers needing large samples of ancient ice that cannot be acquired from a conventional ice core. The scope of the project is broadly an effort to understand the changes in the atmosphere and climate in the past, with implications for future climate and sea level in a warming world.
Jobs Summary: Professor – PI to oversee all aspects of project which includes oversight of design and construction of wide-diameter (10 ) ice core drill to ensure it meets scientific specifications. Staff Research Assocate – technician who runs laboratory, will curate the samples from Taylor Glacier, assist graduate student in performing gas analyses. Graduate Student – work with Professor on project, perform gas analyses, co-author scientific publications. (Total jobs reported: 1)
Project Status: Less Than 50% Completed
This award's data was last updated on Jun. 19, 2009. Help expand these official descriptions using the wiki below.
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