Monthly trends of methane emissions in Los Angeles from 2011 to 2015 inferred...

The core information for this publication's citation.: 
Wong, C. K., T. Pongetti, T. Oda, P. Rao, K. Gurney, S. Newman, R. Duren, C. E. Miller, Y. L. Yung, and S. P. Sander (2016), Monthly trends of methane emissions in Los Angeles from 2011 to 2015 inferred by CLARS-FTS observations, Atmos. Chem. Phys., 16, 13121-13130, doi:10.5194/acp-16-13121-2016.

This paper presents an analysis of methane emissions from the Los Angeles Basin at monthly timescales across a 4-year time period – from September 2011 to August 2015. Using observations acquired by a ground-based nearinfrared remote sensing instrument on Mount Wilson, California, combined with atmospheric CH4 –CO2 tracer–tracer correlations, we observed −18 to +22 % monthly variability in CH4 : CO2 from the annual mean in the Los Angeles Basin. Top-down estimates of methane emissions for the basin also exhibit significant monthly variability (−19 to +31 % from annual mean and a maximum month-to-month change of 47 %). During this period, methane emissions consistently peaked in the late summer/early fall and winter. The estimated annual methane emissions did not show a statistically significant trend over the 2011 to 2015 time period.

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Research Program: 
Atmospheric Composition
Tropospheric Composition Program (TCP)
Upper Atmosphere Research Program (UARP)