Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 17, 7839-7851, 2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
29 Jun 2017
Estimating the size of a methane emission point source at different scales: from local to landscape
Stuart N. Riddick1,a, Sarah Connors1, Andrew D. Robinson1, Alistair J. Manning2, Pippa S. D. Jones1, David Lowry3, Euan Nisbet3, Robert L. Skelton4, Grant Allen5, Joseph Pitt5, and Neil R. P. Harris6 1Centre for Atmospheric Science, University of Cambridge, Cambridge CB2 1EZ, UK
2Met Office, Exeter EX1 3PB, UK
3Department of Earth Sciences, Royal Holloway, University of London, Egham TW20 0EX, UK
4Department of Chemical Engineering, University of Cambridge, Cambridge CB2 3RA, UK
5Centre for Atmospheric Science, University of Manchester, Manchester M13 9PL, UK
6Centre for Atmospheric Informatics and Emissions Technology, Cranfield University, Cranfield MK43 0AL, UK
anow at: Department of Civil and Environmental Engineering, Princeton University, Princeton, 08544, USA
Abstract. High methane (CH4) mixing ratios (up to 4 ppm) have occurred sporadically at our measurement site in Haddenham, Cambridgeshire, since July 2012. Isotopic measurements and back trajectories show that the source is the Waterbeach Waste Management Park 7 km SE of Haddenham. To investigate this further, measurements were made on 30 June and 1 July 2015 at other locations nearer to the source. Landfill emissions have been estimated using three different approaches at different scales; near source using the WindTrax inversion dispersion model, middle distance using a Gaussian plume (GP) model and at the landscape scale using the Numerical Atmospheric Modelling Environment (NAME) Inversion Technique for Emission Modelling (InTEM) inversion. The emission estimates derived using the WindTrax and Gaussian plume (GP) approaches agree well for the period of intense observations. Applying the Gaussian plume approach to all periods of elevated measurements seen at Haddenham produces year-round and monthly landfill emission estimates with an estimated annual emission of 11.6 Gg CH4 yr−1. The monthly emission estimates are highest in winter (2160 kg h−1 in February) and lowest in summer (620 kg h−1 in July). These data identify the effects of environmental conditions on landfill CH4 production and highlight the importance of year-round measurements to capture seasonal variability in CH4 emission.

Citation: Riddick, S. N., Connors, S., Robinson, A. D., Manning, A. J., Jones, P. S. D., Lowry, D., Nisbet, E., Skelton, R. L., Allen, G., Pitt, J., and Harris, N. R. P.: Estimating the size of a methane emission point source at different scales: from local to landscape, Atmos. Chem. Phys., 17, 7839-7851,, 2017.
Publications Copernicus
Short summary
High methane mixing ratios occurred at our long-term measurement site. Isotopic measurements show the source is a landfill 7 km away; the emissions were estimated using three different approaches. The emission estimates made by near-source and middle-distance methods agree well for a period of intense observation. The estimate of the inverse modelling is similar to the labour-intensive middle-distance approach, which shows it can be used to identify point sources within an emission landscape.
High methane mixing ratios occurred at our long-term measurement site. Isotopic measurements...