A cautionary tale: a study of a methane enhancement over the North Sea
Airborne measurements of a methane (CH4) plume over the North Sea from August 2013 are analyzed. The plume was only observed downwind of circumnavigated gas fields, and three methods are used to determine its source. First, a mass balance calculation assuming a gas field source gives a CH4 emission...
Published in: | Journal of Geophysical Research: Atmospheres |
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Online Access: | https://research.manchester.ac.uk/en/publications/7fdff943-4ac8-4a1b-8364-2df61cf98b40 https://doi.org/10.1002/2017JD026626 https://pure.manchester.ac.uk/ws/files/57488787/Cain_et_al_2017_Journal_of_Geophysical_Research_Atmospheres.pdf |
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ftumanchesterpub:oai:pure.atira.dk:publications/7fdff943-4ac8-4a1b-8364-2df61cf98b40 2023-11-12T04:22:31+01:00 A cautionary tale: a study of a methane enhancement over the North Sea Cain, Michelle Warwick, Nicola Fisher, Rebecca E Lowry, David Lanoiselle, Mathias Nisbet, Euan France, James Pitt, Joseph O'Shea, Sebastian Bower, Keith Allen, Grant Illingworth, Samuel Manning, Alastair Bauguitte, Stephane J-B Pisso, Ignacio Pyle, John A. 2017 application/pdf https://research.manchester.ac.uk/en/publications/7fdff943-4ac8-4a1b-8364-2df61cf98b40 https://doi.org/10.1002/2017JD026626 https://pure.manchester.ac.uk/ws/files/57488787/Cain_et_al_2017_Journal_of_Geophysical_Research_Atmospheres.pdf eng eng info:eu-repo/semantics/openAccess Cain , M , Warwick , N , Fisher , R E , Lowry , D , Lanoiselle , M , Nisbet , E , France , J , Pitt , J , O'Shea , S , Bower , K , Allen , G , Illingworth , S , Manning , A , Bauguitte , S J-B , Pisso , I & Pyle , J A 2017 , ' A cautionary tale: a study of a methane enhancement over the North Sea ' , Journal of Geophysical Research: Atmospheres . https://doi.org/10.1002/2017JD026626 methane oil rigs article 2017 ftumanchesterpub https://doi.org/10.1002/2017JD026626 2023-10-30T09:17:34Z Airborne measurements of a methane (CH4) plume over the North Sea from August 2013 are analyzed. The plume was only observed downwind of circumnavigated gas fields, and three methods are used to determine its source. First, a mass balance calculation assuming a gas field source gives a CH4 emission rate between 2.5 ± 0.8×104 and 4.6 ± 1.5×104 kg h−1. This would be greater than the industry's reported 0.5% leak rate if it were emitting for more than half the time. Second, annual average UK CH4 emissions are combined with an atmospheric dispersion model to create pseudo-observations. Clean air from the North Atlantic passed over mainland UK, picking up anthropogenic emissions. To best explain the observed plume using pseudo-observations, an additional North Sea source from the gas rigs area is added. Third, the δ13C-CH4 from the plume is shown to be −53‰, which is lighter than fossil gas but heavier than the UK average emission. We conclude that either an additional small-area mainland source is needed, combined with temporal variability in emission or transport in small-scale meteorological features. Alternatively, a combination of additional sources that are at least 75% from the mainland (−58‰) and up to 25% from the North Sea gas rigs area (−32‰) would explain the measurements. Had the isotopic analysis not been performed, the likely conclusion would have been of a gas field source of CH4. This demonstrates the limitation of analyzing mole fractions alone, as the simplest explanation is rejected based on analysis of isotopic data. Article in Journal/Newspaper North Atlantic The University of Manchester: Research Explorer Journal of Geophysical Research: Atmospheres 122 14 7630 7645 |
institution |
Open Polar |
collection |
The University of Manchester: Research Explorer |
op_collection_id |
ftumanchesterpub |
language |
English |
topic |
methane oil rigs |
spellingShingle |
methane oil rigs Cain, Michelle Warwick, Nicola Fisher, Rebecca E Lowry, David Lanoiselle, Mathias Nisbet, Euan France, James Pitt, Joseph O'Shea, Sebastian Bower, Keith Allen, Grant Illingworth, Samuel Manning, Alastair Bauguitte, Stephane J-B Pisso, Ignacio Pyle, John A. A cautionary tale: a study of a methane enhancement over the North Sea |
topic_facet |
methane oil rigs |
description |
Airborne measurements of a methane (CH4) plume over the North Sea from August 2013 are analyzed. The plume was only observed downwind of circumnavigated gas fields, and three methods are used to determine its source. First, a mass balance calculation assuming a gas field source gives a CH4 emission rate between 2.5 ± 0.8×104 and 4.6 ± 1.5×104 kg h−1. This would be greater than the industry's reported 0.5% leak rate if it were emitting for more than half the time. Second, annual average UK CH4 emissions are combined with an atmospheric dispersion model to create pseudo-observations. Clean air from the North Atlantic passed over mainland UK, picking up anthropogenic emissions. To best explain the observed plume using pseudo-observations, an additional North Sea source from the gas rigs area is added. Third, the δ13C-CH4 from the plume is shown to be −53‰, which is lighter than fossil gas but heavier than the UK average emission. We conclude that either an additional small-area mainland source is needed, combined with temporal variability in emission or transport in small-scale meteorological features. Alternatively, a combination of additional sources that are at least 75% from the mainland (−58‰) and up to 25% from the North Sea gas rigs area (−32‰) would explain the measurements. Had the isotopic analysis not been performed, the likely conclusion would have been of a gas field source of CH4. This demonstrates the limitation of analyzing mole fractions alone, as the simplest explanation is rejected based on analysis of isotopic data. |
format |
Article in Journal/Newspaper |
author |
Cain, Michelle Warwick, Nicola Fisher, Rebecca E Lowry, David Lanoiselle, Mathias Nisbet, Euan France, James Pitt, Joseph O'Shea, Sebastian Bower, Keith Allen, Grant Illingworth, Samuel Manning, Alastair Bauguitte, Stephane J-B Pisso, Ignacio Pyle, John A. |
author_facet |
Cain, Michelle Warwick, Nicola Fisher, Rebecca E Lowry, David Lanoiselle, Mathias Nisbet, Euan France, James Pitt, Joseph O'Shea, Sebastian Bower, Keith Allen, Grant Illingworth, Samuel Manning, Alastair Bauguitte, Stephane J-B Pisso, Ignacio Pyle, John A. |
author_sort |
Cain, Michelle |
title |
A cautionary tale: a study of a methane enhancement over the North Sea |
title_short |
A cautionary tale: a study of a methane enhancement over the North Sea |
title_full |
A cautionary tale: a study of a methane enhancement over the North Sea |
title_fullStr |
A cautionary tale: a study of a methane enhancement over the North Sea |
title_full_unstemmed |
A cautionary tale: a study of a methane enhancement over the North Sea |
title_sort |
cautionary tale: a study of a methane enhancement over the north sea |
publishDate |
2017 |
url |
https://research.manchester.ac.uk/en/publications/7fdff943-4ac8-4a1b-8364-2df61cf98b40 https://doi.org/10.1002/2017JD026626 https://pure.manchester.ac.uk/ws/files/57488787/Cain_et_al_2017_Journal_of_Geophysical_Research_Atmospheres.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Cain , M , Warwick , N , Fisher , R E , Lowry , D , Lanoiselle , M , Nisbet , E , France , J , Pitt , J , O'Shea , S , Bower , K , Allen , G , Illingworth , S , Manning , A , Bauguitte , S J-B , Pisso , I & Pyle , J A 2017 , ' A cautionary tale: a study of a methane enhancement over the North Sea ' , Journal of Geophysical Research: Atmospheres . https://doi.org/10.1002/2017JD026626 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1002/2017JD026626 |
container_title |
Journal of Geophysical Research: Atmospheres |
container_volume |
122 |
container_issue |
14 |
container_start_page |
7630 |
op_container_end_page |
7645 |
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1782337556939014144 |