Source Apportionment of Ambient Methane Enhancements in Los Angeles, California, To Evaluate Emission Inventory Estimates.

Rapid increase in atmospheric methane (CH) 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 emission reduction and mitigation strategies to addresses near-term climate change. This study collected long-term ambient CH measurements at Mount Wilson Observatory (MWO) in Los Angeles, California, to estimate the annual CH emissions from the portion of Los Angeles County that is within the South Coast Air Basin (SCLA).