Carbon monoxide isotopic measurements in Indianapolis constrain urban source isotopic signatures and support mobile fossil fuel emissions as the dominant wintertime CO source

Elementa: Science of the Anthropocene

Scott J. Richardson¹  Kevin Gurney²  Vasilii V. Petrenko³  James W.C. White⁴  Bruce Vaughn⁴  Philip F. Place⁵  Anna Karion⁵  Jocelyn C. Turnbull⁶  Colm Sweeney⁷  Risa Patarasuk⁷  Natasha L. Miles⁸  Isaac J. Vimont⁹ 

[1] National Oceanic and Atmospheric Administration, Boulder, Colorado;and National Institute of Standards and Technology, Gaithersberg, MD;and University of Colorado, CIRIES, Boulder, Colorado, US;Arizona State University, Tempe, AZ;Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY;GNS Science, Lower Hutt, NZ;Pennsylvania State University, College Station, PA;University of Colorado, CIRIES;University of Colorado, INSTAAR, Boulder, Colorado;

关键词: Carbon Monoxide;    Isotopes;    Urban;   

DOI  :  10.1525/elementa.136

来源: DOAJ

【 摘 要 】

We present measurements of CO mole fraction and CO stable isotopes (δ13CO and δC18O) in air during the winters of 2013–14 and 2014–15 at tall tower sampling sites in and around Indianapolis, USA. A tower located upwind of the city was used to quantitatively remove the background CO signal, allowing for the first unambiguous isotopic characterization of the urban CO source and yielding 13CO of –27.7 ± 0.5‰ VPDB and C18O of 17.7 ± 1.1‰ VSMOW for this source. We use the tower isotope measurements, results from a limited traffic study, as well as atmospheric reaction rates to examine contributions from different sources to the Indianapolis CO budget. Our results are consistent with earlier findings that traffic emissions are the dominant source, suggesting a contribution of 96% or more to the overall Indianapolis wintertime CO emissions. Our results are also consistent with the hypothesis that emissions from a small fraction of vehicles without functional catalytic systems dominate the Indianapolis CO budget.

【 授权许可】

Unknown