Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 16, 13121-13130, 2016
https://doi.org/10.5194/acp-16-13121-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
26 Oct 2016
Monthly trends of methane emissions in Los Angeles from 2011 to 2015 inferred by CLARS-FTS observations
Clare K. Wong1,2,a, Thomas J. Pongetti1, Tom Oda3,4, Preeti Rao1, Kevin R. Gurney5, Sally Newman2, Riley M. Duren1, Charles E. Miller1, Yuk L. Yung2, and Stanley P. Sander1 1NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
2Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA
3Goddard Earth Sciences Technology and Research, Universities Space Research Association, Columbia, Maryland, USA
4Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
5School of Life Sciences, Arizona State University, Tempe, Arizona, USA
acurrently at: California State University, Northridge, California, USA
Abstract. 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 near-infrared 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.

Citation: Wong, C. K., Pongetti, T. J., Oda, T., Rao, P., Gurney, K. R., Newman, S., Duren, R. M., Miller, C. E., Yung, Y. L., and Sander, S. P.: Monthly trends of methane emissions in Los Angeles from 2011 to 2015 inferred by CLARS-FTS observations, Atmos. Chem. Phys., 16, 13121-13130, https://doi.org/10.5194/acp-16-13121-2016, 2016.
Publications Copernicus
Download
Short summary
Methane is the second most important greenhouse gas and a target of new emissions regulations in the United States. Despite its importance, its emissions are poorly understood. In this study, we used a remote sensing instrument located on Mount Wilson to estimate the monthly and annual methane emissions from Los Angeles. Derived methane emissions from Los Angeles showed consistent peaks in late summer/early fall and winter during the study period from 2011 to 2015.
Methane is the second most important greenhouse gas and a target of new emissions regulations in...
Share