ethane; methane; propane; shale gas; surface ozone; air quality
Abstract :
[en] Non-methane hydrocarbons such as ethane are important precursors to tropospheric ozone and aerosols. Using data from a global surface network and atmospheric column observations we show that the steady decline in ethane concentrations that began in the 1970s halted between 2005 and 2010 in most of the Northern Hemisphere, and has since reversed. We calculate a yearly increase in ethane emissions in the Northern Hemisphere of 0.42 (+/-0.19) Tg/yr between mid-2009 and mid-2014. The largest increases in ethane and for the shorter-lived propane are seen over the central and eastern USA, with a spatial distribution that suggests North American oil and natural gas development as the primary source of increasing emissions. By including other co-emitted oil and natural gas non-methane hydrocarbons, we estimate a Northern Hemisphere total non-methane hydrocarbon yearly emission increase of 1.2 (+/-0.8) Tg/yr. Atmospheric chemical transport modelling suggests that these emissions could augment summertime mean surface ozone by several nanomoles per mole near oil and natural gas production regions. Methane/ethane oil and natural gas emission ratios suggest a significant increase in associated methane emissions; however, this increase is inconsistent with observed leak rates in production regions and changes in methane’s global isotopic ratio.
Disciplines :
Earth sciences & physical geography
Author, co-author :
Helmig, Detlev; Institute of Arctic and Alpine Research, University of Colorado, Boulder, USA
Rossabi, Samuel; Institute of Arctic and Alpine Research, University of Colorado, Boulder, USA
Hueber, Jacques; Institute of Arctic and Alpine Research, University of Colorado, Boulder, USA
Tans, Pieter; Earth Systems Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, USA
Montzka, Stephen A.; Earth Systems Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, USA
Masarie, Ken; Earth Systems Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, USA
Thoning, Kirk; Earth Systems Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, USA
Carpenter, Lucy J.; Wolfson Atmospheric Chemistry Laboratories, University of York, UK
Lewis, Alastair C.; National Centre for Atmospheric Science, University of York, UK
Punjabi, Shalini; Wolfson Atmospheric Chemistry Laboratories, University of York, UK
Reimann, Stefan; Laboratory for Air Pollution and Environmental Technology, Empa, Swiss Federal Laboratories for Materials Science and Technology, Duebendorf, Switzerland
Vollmer, Martin K.; Laboratory for Air Pollution and Environmental Technology, Empa, Swiss Federal Laboratories for Materials Science and Technology, Duebendorf, Switzerland
Steinbrecher, Rainer; Karlsruhe Institute for Technology, Campus Alpine, Garmisch- Partenkirchen, Germany
Hannigan, James W.; National Center for Atmospheric Research, Boulder, USA
Emmons, Louisa K.; National Center for Atmospheric Research, Boulder, USA
Mahieu, Emmanuel ; Université de Liège > Département d'astrophys., géophysique et océanographie (AGO) > Groupe infra-rouge de phys. atmosph. et solaire (GIRPAS)
Franco, Bruno ; Université de Liège > R&D Direction : Chercheurs ULiège en mobilité
Smale, Dan; National Institute of Water and Atmospheric Research, Lauder, New Zealand
Pozzer, Andrea; Max Planck Institute for Chemistry, Mainz, Germany
BELSPO - SPP Politique scientifique - Service Public Fédéral de Programmation Politique scientifique F.R.S.-FNRS - Fonds de la Recherche Scientifique [BE]
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