| Title: | "Source Apportionment of Ambient Methane Enhancements in Los Angeles, California, To Evaluate Emission Inventory Estimates" |
| Author(s): | Kuwayama T; Charrier-Klobas JG; Chen Y; Vizenor NM; Blake DR; Pongetti T; Conley SA; Sander SP; Croes B; Herner JD; |
| Address: | "California Air Resources Board , 1001 I Street , Sacramento , California 95812 , United States. University of California at Irvine , 570 Rowland Hall , Irvine , California 92697 , United States. NASA Jet Propulsion Laboratory , 4800 Oak Grove Drive , Pasadena , California 91109 , United States. Scientific Aviation , 3335 Airport Road Suite B , Boulder , Colorado 80301 , United States" |
| ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
| Abstract: | "Rapid increase in atmospheric methane (CH(4)) mixing ratios over the past century is attributable to the intensification of human activities. Information on spatially explicit source contributions is needed to develop efficient and cost-effective CH(4) emission reduction and mitigation strategies to addresses near-term climate change. This study collected long-term ambient CH(4) measurements at Mount Wilson Observatory (MWO) in Los Angeles, California, to estimate the annual CH(4) emissions from the portion of Los Angeles County that is within the South Coast Air Basin (SCLA). The measurement-based CH(4) emission estimates for SCLA ranged from 3.95 to 4.89 million metric tons (MMT) carbon dioxide equivalent (CO(2)e) per year between 2012 and 2016. Source apportionment of CH(4), CO, CO(2), and volatile organic compounds (VOCs) measurements were used to evaluate source categories that contributed to ambient CH(4) mixing ratio enhancements (DeltaCH(4)) at SCLA between 2014 and 2016. Results suggested DeltaCH(4) contributions of 56-79% from natural gas sources, 7-31% from landfills, and 4-15% from transportation sources. The SCLA-specific CH(4) emission estimate made using a research grade gridded CH(4) emission inventory suggested contributions of 47% from natural gas sources and 50% from landfills. Subsequent airborne measurements determined that CH(4) emissions from two major CH(4) sources in SCLA were significantly smaller in magnitude than previously thought. This study highlights the importance of studying the variabilities of CH(4) emissions across California for policy makers and stakeholders alike" |
| Keywords: | *Air Pollutants Environmental Monitoring Los Angeles *Methane Natural Gas; |
| Notes: | "MedlineKuwayama, Toshihiro Charrier-Klobas, Jessica G Chen, Yanju Vizenor, Nicholas M Blake, Donald R Pongetti, Thomas Conley, Stephen A Sander, Stanley P Croes, Bart Herner, Jorn D eng Research Support, Non-U.S. Gov't 2019/03/02 Environ Sci Technol. 2019 Mar 19; 53(6):2961-2970. doi: 10.1021/acs.est.8b02307. Epub 2019 Mar 1" |
