Construction of a gas-handling system for measurement of bond ordering in methane gas

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This laboratory took delivery of the world?s largest gas-source isotope ratio mass spectrometer. The instrument, referred to as the "Panorama", offers by far the greatest mass resolution of any gas-source isotope ratio instrument. The principle investigators will use the unique capabilities of the new instrument for tracing the provenance of methane gas. This award will provide funding to construct the infrastructure to allow them to process methane gases for isotopic analysis. The benefits of the research program extend beyond basic research to include numerous (and some unforeseen) practical applications that benefit society in general. For example, methane is 20 times more effective as a greenhouse gas than is carbon dioxide. An improved understanding of the sources and sinks of atmospheric methane is of clear benefit to society in providing a means for understanding the causes of variations in atmospheric methane concentrations.Identifying the sources of methane gas with certainty in any particular occurrence has been until now, inexact, but the use of isotopic bond ordering holds the promise of greater certainty. The origins of natural gas and the highly uncertain global budget of methane gas in the atmosphere are two target applications of this novel approach for tracing the sources of methane. Bond ordering will afford temperatures of formation where thermodynamic equilibrium applies. Analyzing both 13CH3D/12CH4 and 12CH2D2/12CH4 will provide evidence for mixing of sources where it has occurred, thus disambiguating the meaning of standard bulk isotope ratios. These isotopologue ratios are also predicted to provide diagnostic patterns for different kinetic pathways involving transport, formation, or destruction of methane.