A14F-04
Fluxes of Greenhouse Gases from the Baltimore-Washington Area: Results from WINTER 2015 Aircraft Observations
Monday, 14 December 2015: 16:39
3012 (Moscone West)
Russell R Dickerson1, Xinrong Ren2, Paul B Shepson3, Olivia Elizabeth Salmon4, Steven S Brown5, Joel A Thornton6, James R Whetstone7, Ross J Salawitch8, Sayantan Sahu8, Dolly Hall8, Courtney Grimes8 and Tamae M Wong7, (1)University of Maryland College Park, College Park, MD, United States, (2)NOAA Science Center, College Park, MD, United States, (3)Purdue University, West Lafayette, IN, United States, (4)Purdue University, Chemistry, West Lafayette, IN, United States, (5)NOAA Boulder, Boulder, CO, United States, (6)Univ Washington - Seattle, Seattle, WA, United States, (7)National Institute of Standards and Technology Gaithersburg, Gaithersburg, MD, United States, (8)University of Maryland, College Park, MD, United States
Abstract:
Urban areas are responsible for a major component of the anthropogenic greenhouse gas (GHG) emissions. Quantification of urban GHG fluxes is important for establishing scientifically sound and cost-effective policies for mitigating GHGs. Discrepancies between observations and model simulations of GHGs suggest uncharacterized sources in urban environments. In this work, we analyze and quantify fluxes of CO2, CH4, CO (and other trace species) from the Baltimore-Washington area based on the mass balance approach using the two-aircraft observations conducted in February-March 2015. Estimated fluxes from this area were 110,000±20,000 moles s-1 for CO2, 700±330 moles s-1 for CH4, and 535±188 moles s-1 for CO. This implies that methane is responsible for ~20% of the climate forcing from these cities. Point sources of CO2 from four regional power plants and one point source of CH4 from a landfill were identified and the emissions from these point sources were quantified based on the aircraft observation and compared to the emission inventory data. Methane fluxes from the Washington area were larger than from the Baltimore area, indicating a larger leakage rate in the Washington area. The ethane-to-methane ratios, with a mean of 3.3%, in the limited canister samples collected during the flights indicate that natural gas leaks and the upwind oil and natural gas operations are responsible for a substantial fraction of the CH4 flux. These observations will be compared to models using Ensemble Kalman Filter Assimilation techniques.
