Is There Cosmogenic Radiomethane in Polar Firn?

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

Proposal: Is There Cosmogenic Radiomethane in Polar Firn? P.I.: Jeffrey P Severinghaus University of California-San Diego Scripps Inst of Oceanography Proposal # 0806450 Researchers at the University of California - San Diego?s Scripps Institute of Oceanography have received funding to test the hypothesis that cosmic rays produce small amounts of the 14C isotope of methane (14CH4) in the upper layers of snow turning in to ice (firn). This research will help determine present and past sources of methane in the atmosphere and refine our understanding of methane?s role in climate warming. Methane and other gases will be extracted from firn at Summit, Greenland by melting 1.5 tons of firn under vacuum. The ratio of 14CH4 to 12CH4 will be determined to test the hypothesis that cosmic rays generate 14C atoms that react with hydrogen to produce 14CH4 in the ice. The study is expected to provide a definitive test of the hypothesis that fossil sources of methane contributed to the rapid increases in methane concentration at the end of the last glacial period.