Chemical Feedback From Decreasing Carbon Monoxide Emissions

B. Gaubert, H. M. Worden, A. F.J. Arellano, L. K. Emmons, S. Tilmes, J. Barré, S. Martinez Alonso, F. Vitt, J. L. Anderson, F. Alkemade, S. Houweling, D. P. Edwards

Research output: Contribution to journalArticlepeer-review

51 Scopus citations


Understanding changes in the burden and growth rate of atmospheric methane (CH4) has been the focus of several recent studies but still lacks scientific consensus. Here we investigate the role of decreasing anthropogenic carbon monoxide (CO) emissions since 2002 on hydroxyl radical (OH) sinks and tropospheric CH4 loss. We quantify this impact by contrasting two model simulations for 2002–2013: (1) a Measurement of the Pollution in the Troposphere (MOPITT) CO reanalysis and (2) a Control-Run without CO assimilation. These simulations are performed with the Community Atmosphere Model with Chemistry of the Community Earth System Model fully coupled chemistry climate model with prescribed CH4 surface concentrations. The assimilation of MOPITT observations constrains the global CO burden, which significantly decreased over this period by ~20%. We find that this decrease results to (a) increase in CO chemical production, (b) higher CH4 oxidation by OH, and (c) ~8% shorter CH4 lifetime. We elucidate this coupling by a surrogate mechanism for CO-OH-CH4 that is quantified from the full chemistry simulations.

Original languageEnglish (US)
Pages (from-to)9985-9995
Number of pages11
JournalGeophysical Research Letters
Issue number19
StatePublished - Oct 16 2017


  • air pollution
  • chemistry climate modeling
  • data assimilation
  • global chemistry transport model
  • tropospheric composition

ASJC Scopus subject areas

  • Geophysics
  • General Earth and Planetary Sciences


Dive into the research topics of 'Chemical Feedback From Decreasing Carbon Monoxide Emissions'. Together they form a unique fingerprint.

Cite this