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Area fluxes of carbon dioxide, methane, and carbon monoxide derived from airborne measurements around Greater London: A case study during summer 2012
Author(s) -
O'Shea Sebastian J.,
Allen Grant,
Fleming Zoë L.,
Bauguitte Stephane J.B.,
Percival Carl J.,
Gallagher Martin W.,
Lee James,
Helfter Carole,
Nemitz Eiko
Publication year - 2014
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2013jd021269
Subject(s) - carbon monoxide , carbon dioxide , methane , trace gas , environmental science , atmospheric sciences , outflow , inflow , carbon fibers , greenhouse gas , meteorology , chemistry , materials science , geography , physics , geology , biochemistry , organic chemistry , catalysis , oceanography , composite number , composite material
Airborne measurements of thermodynamic properties and carbon dioxide (CO 2 ), methane (CH 4 ), and carbon monoxide (CO) mole fractions were recorded on board the FAAM BAe‐146 UK research aircraft and used to characterize the inflow and outflow from Greater London on 30 July 2012. All three trace gases were observed to be significantly enhanced downwind of Greater London with spatially resolved plumes of comparable extent and position. A mass budget calculation using a box model approach (and uncertainty propagation) was used to determine net regional fluxes of 21 ± 3 µmol CO 2 m −2 s −1 , 0.13 ± 0.02 µmol CH 4 m −2 s −1 , and 0.12 ± 0.02 µmol CO m −2 s −1 for Greater London. These fluxes are comparable with simultaneous surface observations and previous studies in urban environments. A comparison was made with the 2010 UK National Atmospheric Emissions Inventory (NAEI), and fluxes from this study are found to be factors 2.3 for CO 2 and 2.2 for CO larger than those estimated by the spatially disaggregated NAEI (2011) for Greater London. Fluxes of CH 4 were found to be a factor 3.4 larger than the UK NAEI (2009). The efficacy of this mass balance approach, in general, is also discussed in terms of key assumptions and uncertainties, and we offer advice for future studies on how uncertainties could be reduced.