1Department of Chemistry, University of York, York, UK
2Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada
3NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
4Department of Physics, New Mexico Institute of Mining and Technology, Socorro, New Mexico, USA
5Department of Earth and Planetary Sciences and Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
6Department of Environmental Science and Engineering, Tsinghua University, Beijing, China
7Department of Geological and Mining Engineering and Sciences & Department of Civil and Environmental Engineering, Michigan Technological University, Houghton MI, USA
8EOS Group, College of Science and Engineering, University of Leicester, UK
9School of GeoSciences, University of Edinburgh, UK
10Atmospheric and Environmental Research, Inc., Lexington, MA, USA
11Department of Atmospheric and Oceanic Science, School of Physics, Peking University, China
Received: 26 Nov 2010 – Discussion started: 28 Apr 2011
Abstract. Near global upper tropospheric concentrations of carbon monoxide (CO), ethane (C2H6) and ethyne (C2H2) from ACE (Atmospheric Chemistry Experiment) Fourier transform spectrometer on board the Canadian satellite SCISAT-1 are presented and compared with the output from the Chemical Transport Model (CTM) GEOS-Chem. The retrievals of ethane and ethyne from ACE have been improved for this paper by using new sets of microwindows compared with those for previous versions of ACE data. With the improved ethyne retrieval we have been able to produce a near global upper tropospheric distribution of C2H2 from space. Carbon monoxide, ethane and ethyne concentrations retrieved using ACE spectra show the expected seasonality linked to variations in the anthropogenic emissions and destruction rates as well as seasonal biomass burning activity. The GEOS-Chem model was run using the dicarbonyl chemistry suite, an extended chemical mechanism in which ethyne is treated explicitly. Seasonal cycles observed from satellite data are well reproduced by the model output, however the simulated CO concentrations are found to be systematically biased low over the Northern Hemisphere. An average negative global mean bias of 12% and 7% of the model relative to the satellite observations has been found for CO and C2H6 respectively and a positive global mean bias of 1% has been found for C2H2. ACE data are compared for validation purposes with MkIV spectrometer data and Global Tropospheric Experiment (GTE) TRACE-A campaign data showing good agreement with all of them.
Revised: 19 Aug 2011 – Accepted: 15 Sep 2011 – Published: 27 Sep 2011
González Abad, G., Allen, N. D. C., Bernath, P. F., Boone, C. D., McLeod, S. D., Manney, G. L., Toon, G. C., Carouge, C., Wang, Y., Wu, S., Barkley, M. P., Palmer, P. I., Xiao, Y., and Fu, T. M.: Ethane, ethyne and carbon monoxide concentrations in the upper troposphere and lower stratosphere from ACE and GEOS-Chem: a comparison study, Atmos. Chem. Phys., 11, 9927-9941, doi:10.5194/acp-11-9927-2011, 2011.