Source Attribution of Methane Emissions in Northeastern Colorado Using Ammonia to Methane Emission Ratios

Monday, 14 December 2015
Poster Hall (Moscone South)
Scott Joseph Eilerman1,2, J A Neuman3, Jeff Peischl1, Kenneth C. Aikin4, Thomas B Ryerson5, Anne Elizabeth Perring1, Ellis Shipley Robinson1,2, Maxwell Holloway6 and Michael Trainer7, (1)Cooperative Institute for Research in Environmental Sciences, Boulder, CO, United States, (2)NOAA Earth System Research Lab, Boulder, CO, United States, (3)CIRES, Boulder, CO, United States, (4)Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, United States, (5)NOAA, Boulder, CO, United States, (6)Science and Technology Corporation, Boulder, CO, United States, (7)NOAA ESRL Chemical Sciences Division, Boulder, CO, United States
Due to recent advances in extraction technology, oil and natural gas extraction and processing in the Denver-Julesburg basin has increased substantially in the past decade. Northeastern Colorado is also home to over 250 concentrated animal feeding operations (CAFOs), capable of hosting over 2 million head of ruminant livestock (cattle and sheep). Because of methane’s high Global Warming Potential, quantification and attribution of methane emissions from oil and gas development and agricultural activity are important for guiding greenhouse gas emission policy. However, due to the co-location of these different sources, top-down measurements of methane are often unable to attribute emissions to a specific source or sector. In this work, we evaluate the ammonia:methane emission ratio directly downwind of CAFOs using a mobile laboratory. Several CAFOs were chosen for periodic study over a 12-month period to identify diurnal and seasonal variation in the emission ratio as well as differences due to livestock type. Using this knowledge of the agricultural ammonia:methane emission ratio, aircraft measurements of ammonia and methane over oil and gas basins in the western US during the Shale Oil and Natural Gas Nexus (SONGNEX) field campaign in March and April 2015 can be used for source attribution of methane emissions.