References

ACPD

Atmospheric Chemistry and Physics Discussions

ACPD

1680-7375

Copernicus GmbH

Göttingen, Germany

10.5194/acpd-9-17297-2009

Fluxes and concentrations of volatile organic compounds above central London, UK

Langford

¹ ² Nemitz

² House

² ³ Phillips

G. J.

² Famulari

² Davison

¹ Hopkins

J. R.

⁴ Lewis

A. C.

⁴ Hewitt

C. N.

Lancaster Environment Centre, Lancaster University, LA1 4YQ, UK

Biogeochemistry Programme, Centre for Ecology and Hydrology, Bush Estate, EH26 0QB, Edinburgh, UK

School of Chemistry, Edinburgh University, West Mains Road, EH9 3JJ, Edinburgh, UK

National Centre for Atmospheric Science, University of York, York, YO10 5DD, UK

14 08 2009

9 4 17297 17333

This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

This article is available from http://www.atmos-chem-phys-discuss.net/9/17297/2009/acpd-9-17297-2009.html

The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/9/17297/2009/acpd-9-17297-2009.pdf

Concentrations and fluxes of eight volatile organic compounds (VOCs) were measured during October 2006 from a high telecom tower above central London, as part of the CityFlux contribution to the REPARTEE I campaign. A continuous flow disjunct eddy covariance technique with analysis by proton transfer reaction mass spectrometry was used. Daily averaged VOC mixing ratios were within the range 1–19 ppb for the oxygenated compounds (methanol, acetaldehyde and acetone) and 0.2–1.3 ppb for the aromatics (benzene, toluene and ethylbenzene). Typical VOC fluxes were in the range 0.1–1.0 mg m−2 h−1. There was a non-linear relationship between VOC fluxes and traffic density for most of the measured compounds. Traffic activity was estimated to account for approximately 70% of the aromatic compound fluxes, whereas non-traffic related sources were found to be more important for methanol and isoprene fluxes. The measured fluxes were comparable to the estimates of the UK national atmospheric emission inventory for the aromatic VOCs and CO. In contrast, fluxes of the oxygenated compounds were about three times larger than inventory estimates. For isoprene and acetonitrile this difference was many times larger. At temperatures over 25°C it is estimated that more than half the isoprene observed in central London is of biogenic origin.

References 1

Ammann, C., Brunner, A., Spirig, C., and Neftel, A.: Technical note: Water vapour concentration and flux measurements with PTR-MS, Atmos. Chem. Phys., 6, 4643–4651, 2006.

Baker, A. K., Beyersdorf, A. J., Doezema, L. A., Katzenstein, A., Meinardi, S., Simpson, I. J., Blake, D. R., and Rowland, F. S.: Measurements of non-methane hydrocarbons in 28 United States cities, Atmos. Environ., 42, 170–182, 2008.

Barlow, J. F., Dunbar, T. M., Nemitz, E., Wood, C. R., Gallagher, M., Davies, F., O'Connor, E., and Harrison, R.: Boundary layer dynamics over London, UK as observed using Doppler lidar, Atmos. Chem. Phys. Discuss., in preparation, 2009.

Brunner, A., Ammann, C., Neftel, A., and Spirig, C.: Methanol exchange between grassland and the atmosphere, Biogeosciences, 4, 395–410, 2007.

Dall'Osto, M., Harrison, R., Nemitz, E., et al.: The REPARTEE Experiment: Overview of the Campaigns in London in 2006 and 2007, Atmos. Chem. Phys. Discuss., in preparation, 2009.

de Gouw, J. and Warneke, C.: Measurements of volatile organic compounds in the Earth's atmosphere using proton transfer reaction-mass spectrometry, Mass Spectrom. Rev., 26, 223–257, 2007.

Davison, B., Taipale, R., Langford, B., Misztal, P., Fares, S., Matteucci, G., Loreto, F., Cape, J. N., Rinne, J., and Hewitt, C. N.: Concentrations and fluxes of biogenic volatile organic compounds above a Mediterranean macchia ecosystem in western Italy, Biogeosciences, 6, 1655–1670, 2009.

Dorsey, J. R., Nemitz, E., Gallagher, M. W., Fowler, D., Williams, P. I., Bower, K. N., and Beswick, K. M.: Direct measurements and parameterisation of aerosol flux, concentration and emission velocity above a city, Atmos. Environ., 36, 791–800, 2002.

Dumitrean, P.: Annual summary of data produced by the UK Ambient Automatic Hydrocarbon Air Quality Network, 2007, Report AEAT/ENV/R/2797, AEA Technology plc, Harwell, UK, http://www.airquality.co.uk/reports/cat13/0904221401_2007_annual_rep_issue1.pdf, 2008.

Famulari, D., Nemitz, E., Di Marco, C., Phillips, G. J., Thomas, R., House, E., and Fowler, D.: Eddy-covariance measurements of nitrous oxide fluxes above a city, Agric. Forest Meteorol., in press, 2009.

Finnigan, J. J., Clement, R., Malhi, Y., Leuning, R., and Cleugh, H. A.: A re-evaluation of long-term flux measurement techniques – part i: Averaging and coordinate rotation, Bound.-Layer Meteorol., 107, 1–48, 2003.

Foken, T. and Wichura, B.: Tools for quality assessment of surface-based flux measurements, Agr. Forest Meteorol., 78, 83–105, 1996.

Foken, T., Göckede, M., Mauder, M., Mahrt, L., Amiro, B., and Munger, W.: Post-field data quality control, in: Handbook of Micrometeorology: A guide for surface flux measurement and analysis, edited by: Lee, W. M. X. and Law,B., Dordrecht, Kluer Academic Publishers, 29, 181–203, 2004.

Grabmer, W., Graus, M., Lindinger, C., Wisthaler, A., Rappengluck, B., Steinbrecher, R., and Hansel, A.: Disjunct eddy covariance measurements of monoterpene fluxes from a Norway spruce forest using PTR-MS, Int. J. Mass Spectrom., 239, 111–115, 2004.

Hayward, S., Hewitt, C. N., Sartin, J. H., and Owen, S. M.: Performance characteristics and applications of a proton transfer reaction-mass spectrometer for measuring volatile organic compounds in ambient air, Environ. Sci. Technol., 36, 1554–1560, 2002.

Heeb, N. V., Forss, A. M., Bach, C., Reimann, S., Herzog, A., and Jackle, H. W.: A comparison of benzene, toluene and C-2-benzenes mixing ratios in automotive exhaust and in the suburban atmosphere during the introduction of catalytic converter technology to the Swiss car fleet, Atmos. Environ., 34, 3103–3116, 2000.

Helfter, C., Barlow, J. F., Blackall, T., Famulari, D., Grimmond, C. S. B., Pappas, V., Phillips, G. J., Wood, C. R., and Nemitz, E.: Long-term measurements of CO2 fluxes above London, Atmos. Chem. Phys. Discuss., in preparation, 2009.

Horst, T. W.: A simple formula for attenuation of eddy fluxes measured with first-order-response scalar sensors, Bound.-Lay. Meteorol., 82, 219–233, 1997.

Jensen, S. S.: Driving patterns and emissions from different types of roads, Sci. Total Environ., 169, 123–128, 1995.

Karl, T., Guenther, A., Lindinger, C., Jordan, A., Fall, R., and Lindinger, W.: Eddy covariance measurements of oxygenated volatile organic compound fluxes from crop harvesting using a redesigned proton-transfer-reaction mass spectrometer, J. Geophys. Res.-Atmos., 106, 24157–24167, 2001.

Karl, T. G., Spirig, C., Rinne, J., Stroud, C., Prevost, P., Greenberg, J., Fall, R., and Guenther, A.: Virtual disjunct eddy covariance measurements of organic compound fluxes from a subalpine forest using proton transfer reaction mass spectrometry, Atmos. Chem. Phys., 2, 279–291, 2002.

Karl, T., Apel, E., Hodzic, A., Riemer, D. D., Blake, D. R., and Wiedinmyer, C.: Emissions of volatile organic compounds inferred from airborne flux measurements over a megacity, Atmos. Chem. Phys., 9, 271–285, 2009.

Kljun, N., Calanca, P., Rotachhi, M. W., and Schmid, H. P.: A simple parameterisation for flux footprint predictions, Bound.-Lay. Meteorol., 112, 503–523, 2004.

Langford, B., Davison, B., Nemitz, E., and Hewitt, C. N.: Mixing ratios and eddy covariance flux measurements of volatile organic compounds from an urban canopy (Manchester, UK), Atmos. Chem. Phys., 9, 1971–1987, 2009.

Lee, A., Schade, G. W., Holzinger, R., and Goldstein, A. H.: A comparison of new measurements of total monoterpene flux with improved measurements of speciated monoterpene flux, Atmos. Chem. Phys., 5, 505–513, 2005.

Lindinger, W., Hansel, A., and Jordan, A.: Proton-transfer-reaction mass spectrometry (PTR-MS): On-line monitoring of volatile organic compounds at pptv levels, Chem. Soc. Rev., 27, 347–354, 1998.

Loreto, F. and Sharkey, T. D.: A gas-exchange study of photosynthesis and isoprene emission in Quercus-rubra l, Planta, 182, 523–531, 1990.

Moncrieff J., Finnigan R. C. J., and Meyers T.: Averaging, detrending, and filtering of eddy covariance time series, in: Handbook of Micrometeorology: A guide for surface flux measurement and analysis, edited by: Lee, W. M. X. and Law, B., Dordrecht, Kluer Academic Publishers, 29, 7–30, 2004.

NAEI, National Atmospheric Emission Inventory, 2006.

Nemitz, E., Hargreaves, K. J., McDonald, A. G., Dorsey, J. R., and Fowler, D.: Meteorological measurements of the urban heat budget and CO2 emissions on a city scale, Environ. Sci. Technol., 36, 3139–3146, 2002.

Nemitz, E., Jimenez, J. L., Huffman, J. A., Ulbrich, I. M., Canagaratna, M. R., Worsnop, D. R., and Guenther, A. B.: An eddy-covariance system for the measurement of surface/atmosphere exchange fluxes of submicron aerosol chemical species – first application above an urban area, Aerosol Sci. Technol., 42, 636–657, 2008.

Oke, T. R.: Towards better scientific communication in urban climate, Theor. Appl. Climatol., 84, 179–190, 2006.

Park, C., Schade, G., and Boedeker, I.: VOC flux measurements using a novel relaxed eddy accumulation GC-FID system in urban Houston, Texas. Eos Trans. AGU, 89(53), Fall Meet. Suppl., Abstract A41F-0178, 2008.

Phillips, G. J., Famulari, D., Thomas, R., and Nemitz, E.: Fluxes of CO and CO2 above two UK urban areas, Atmos. Chem. Phys. Discuss., in preparation, 2009a.

Phillips, G. J., Thomas, R., Di Marco, C. F., and Nemitz, E.: Fluxes of submicron organic aerosol above three UK urban areas, Atmos. Chem. Phys. Discuss., in preparation, 2009b.

Rinne, H. J. I., Guenther, A. B., Warneke, C., de Gouw, J. A., and Luxembourg, S. L.: Disjunct eddy covariance technique for trace gas flux measurements, Geophys. Res. Lett., 28, 3139–3142, 2001.

Spirig, C., Neftel, A., Ammann, C., Dommen, J., Grabmer, W., Thielmann, A., Schaub, A., Beauchamp, J., Wisthaler, A., and Hansel, A.: Eddy covariance flux measurements of biogenic VOCs during ECHO 2003 using proton transfer reaction mass spectrometry, Atmos. Chem. Phys., 5, 465–481, 2005.

Thomas, R.: Measurement of Speciated Aerosol Fluxes, Ph.D. Thesis, University of Manchester, 2007.

UNECE: Protocol to the 1979 Convention on Long-Range Transboundary Air Pollution Concerning the Control of Emissions of Volatile Organic Compounds on their Transboundary Fluxes, ECE/EB.AIR/30, United Nations Economic Commission for Europe, Geneva, Switzerland, 1991..

UNECE: Protocol to the 1979 Convention on Long-range Transboundary Air Pollution to Abate Acidification, Eutrophication and Ground-level Ozone, United Nations Economic Commission for Europe, Geneva, Switzerland, 1999.

Velasco, E., Lamb, B., Pressley, S., Allwine, E., Westberg, H., Jobson, B. T., Alexander, M., Prazeller, P., Molina, L., and Molina, M.: Flux measurements of volatile organic compounds from an urban landscape, Geophys. Res. Lett., 32, L20802, doi:10.1029/2005GL023356, 2005.

Velasco, E., Pressley, S., Grivicke, R., Allwine, E., Coons, T., Foster, W., Jobson, T., Westberg, H., Ramos, R., Hernández, F., Molina, L. T., and Lamb, B.: Eddy covariance flux measurements of pollutant gases in urban Mexico City, Atmos. Chem. Phys. Discuss., 9, 7991–8034, 2009.

Warneke, C., Luxembourg, S. L., de Gouw, J. A., Rinne, H. J. I., Guenther, A. B., and Fall, R.: Disjunct eddy covariance measurements of oxygenated volatile organic compounds fluxes from an alfalfa field before and after cutting, J. Geophys. Res.-Atmos., 107, 107(D8), 4067, doi:10.1029/2001JD000594, 2002.

Wood, C. R., Lacser, A., Barlow, J. F., Pdhra, A., Belcher, S. E., Nemitz, E., Helfter, C., Famulari, D., and Grimmond, C. S. B.: Flow and turbulence atop a tower of 190 metres above London: a climatology, Atmos. Chem. Phys. Discuss., in preparation, 2009.

Zhao, J. and Zhang, R. Y.: Proton transfer reaction rate constants between hydronium ion (H3O$^+)$ and volatile organic compounds, Atmos. Environ., 38, 2177–2185, 2004.