Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 15, 7049-7069, 2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
30 Jun 2015
Estimating global and North American methane emissions with high spatial resolution using GOSAT satellite data
A. J. Turner1, D. J. Jacob1,2, K. J. Wecht2, J. D. Maasakkers1, E. Lundgren1, A. E. Andrews3, S. C. Biraud4, H. Boesch5,6, K. W. Bowman7, N. M. Deutscher8,9, M. K. Dubey10, D. W. T. Griffith8, F. Hase11, A. Kuze12, J. Notholt9, H. Ohyama12,13, R. Parker5,6, V. H. Payne7, R. Sussmann14, C. Sweeney3,15, V. A. Velazco8, T. Warneke9, P. O. Wennberg16, and D. Wunch16 1School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
2Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts, USA
3NOAA Earth System Research Laboratory, Boulder, Colorado, USA
4Lawrence Berkeley National Laboratory, Berkeley, California, USA
5Earth Observation Science Group, Department of Physics and Astronomy, University of Leicester, Leicester, UK
6National Centre for Earth Observation, University of Leicester, Leicester, UK
7Jet Propulsion Laboratory/California Institute of Technology, Pasadena, California, USA
8Centre for Atmospheric Chemistry, University of Wollongong, NSW, Australia
9Institute of Environmental Physics, University of Bremen, Bremen, Germany
10Los Alamos National Laboratory, Los Alamos, New Mexico, USA
11Karlsruhe Institute of Technology, IMK-ASF, Karlsruhe, Germany
12Japan Aerospace Exploration Agency, Tsukuba, Ibaraki, Japan
13Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya, Aichi, Japan
14Karlsruhe Institute of Technology, IMK-IFU, Garmisch-Partenkirchen, Germany
15Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USA
16California Institute of Technology, Pasadena, California, USA
Abstract. We use 2009–2011 space-borne methane observations from the Greenhouse Gases Observing SATellite (GOSAT) to estimate global and North American methane emissions with 4° × 5° and up to 50 km × 50 km spatial resolution, respectively. GEOS-Chem and GOSAT data are first evaluated with atmospheric methane observations from surface and tower networks (NOAA/ESRL, TCCON) and aircraft (NOAA/ESRL, HIPPO), using the GEOS-Chem chemical transport model as a platform to facilitate comparison of GOSAT with in situ data. This identifies a high-latitude bias between the GOSAT data and GEOS-Chem that we correct via quadratic regression. Our global adjoint-based inversion yields a total methane source of 539 Tg a−1 with some important regional corrections to the EDGARv4.2 inventory used as a prior. Results serve as dynamic boundary conditions for an analytical inversion of North American methane emissions using radial basis functions to achieve high resolution of large sources and provide error characterization. We infer a US anthropogenic methane source of 40.2–42.7 Tg a−1, as compared to 24.9–27.0 Tg a−1 in the EDGAR and EPA bottom-up inventories, and 30.0–44.5 Tg a−1 in recent inverse studies. Our estimate is supported by independent surface and aircraft data and by previous inverse studies for California. We find that the emissions are highest in the southern–central US, the Central Valley of California, and Florida wetlands; large isolated point sources such as the US Four Corners also contribute. Using prior information on source locations, we attribute 29–44 % of US anthropogenic methane emissions to livestock, 22–31 % to oil/gas, 20 % to landfills/wastewater, and 11–15 % to coal. Wetlands contribute an additional 9.0–10.1 Tg a−1.

Citation: Turner, A. J., Jacob, D. J., Wecht, K. J., Maasakkers, J. D., Lundgren, E., Andrews, A. E., Biraud, S. C., Boesch, H., Bowman, K. W., Deutscher, N. M., Dubey, M. K., Griffith, D. W. T., Hase, F., Kuze, A., Notholt, J., Ohyama, H., Parker, R., Payne, V. H., Sussmann, R., Sweeney, C., Velazco, V. A., Warneke, T., Wennberg, P. O., and Wunch, D.: Estimating global and North American methane emissions with high spatial resolution using GOSAT satellite data, Atmos. Chem. Phys., 15, 7049-7069,, 2015.
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