Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 5.668 IF 5.668
  • IF 5-year value: 6.201 IF 5-year
    6.201
  • CiteScore value: 6.13 CiteScore
    6.13
  • SNIP value: 1.633 SNIP 1.633
  • IPP value: 5.91 IPP 5.91
  • SJR value: 2.938 SJR 2.938
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 174 Scimago H
    index 174
  • h5-index value: 87 h5-index 87
Volume 7, issue 3
Atmos. Chem. Phys., 7, 587-598, 2007
https://doi.org/10.5194/acp-7-587-2007
© Author(s) 2007. This work is licensed under
the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.

Special issue: The North Atlantic Marine Boundary Layer Experiment (NAMBLEX),...

Atmos. Chem. Phys., 7, 587-598, 2007
https://doi.org/10.5194/acp-7-587-2007
© Author(s) 2007. This work is licensed under
the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.

  07 Feb 2007

07 Feb 2007

Night-time radical chemistry during the NAMBLEX campaign

R. Sommariva1,*, M. J. Pilling1, W. J. Bloss1, D. E. Heard1, J. D. Lee1,**, Z. L. Fleming2, P. S. Monks2, J. M. C. Plane3,***, A. Saiz-Lopez3,****, S. M. Ball4,*****, M. Bitter4, R. L. Jones4, N. Brough3, S. A. Penkett3, J. R. Hopkins5, A. C. Lewis5, and K. A. Read1 R. Sommariva et al.
  • 1School of Chemistry, University of Leeds, Leeds, UK
  • 2Department of Chemistry, University of Leicester, Leicester, UK
  • 3School of Environmental Sciences, University of East Anglia, Norwich, UK
  • 4University Chemical Laboratory, University of Cambridge, Cambridge, UK
  • 5Department of Chemistry, University of York, York, UK
  • *now at: Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA
  • **now at: Department of Chemistry, University of York, York, UK
  • ***now at: School of Chemistry, University of Leeds, Leeds, UK
  • ****now at: NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
  • *****now at: Department of Chemistry, University of Leicester, Leicester, UK

Abstract. Night-time chemistry in the Marine Boundary Layer has been modelled using a number of observationally constrained zero-dimensional box-models. The models were based upon the Master Chemical Mechanism (MCM) and the measurements were taken during the North Atlantic Marine Boundary Layer Experiment (NAMBLEX) campaign at Mace Head, Ireland in July–September 2002.

The model could reproduce, within the combined uncertainties, the measured concentration of HO2 (within 30–40%) during the night 31 August–1 September and of HO2+RO2 (within 15–30%) during several nights of the campaign. The model always overestimated the NO3 measurements made by Differential Optical Absorption Spectroscopy (DOAS) by up to an order of magnitude or more, but agreed with the NO3 Cavity Ring-Down Spectroscopy (CRDS) measurements to within 30–50%. The most likely explanation of the discrepancy between the two instruments and the model is the reaction of the nitrate radical with inhomogeneously distributed NO, which was measured at concentrations of up to 10 ppt, even though this is not enough to fully explain the difference between the DOAS measurements and the model.

A rate of production and destruction analysis showed that radicals were generated during the night mainly by the reaction of ozone with light alkenes. The cycling between HO2/RO2 and OH was maintained during the night by the low concentrations of NO and the overall radical concentration was limited by slow loss of peroxy radicals to form peroxides. A strong peak in [NO2] during the night 31 August–1 September allowed an insight into the radical fluxes and the connections between the HOx and the NO3 cycles.

Publications Copernicus
Special issue
Download
Citation
Share