Ozone photochemistry and elevated isoprene during the UK heatwave of august 2003

James D. Lee, Alastair C. Lewis, Paul S. Monks, Mark Jacob, Jacqueline F. Hamilton, James R. Hopkins, Nicola M. Watson, Julie E. Saxton, Christopher Ennis, Lucy J. Carpenter, Nicola Carslaw, Zoe Fleming, Brian J. Bandy, David E. Oram, Stuart A. Penkett, Jana Slemr, Emily Norton, Andrew R. Rickard, Lisa K Whalley, Dwayne E. HeardWilliam J. Bloss, Thomas Gravestock, Shona C. Smith, Jenny Stanton, Michael J. Pilling, Michael E. Jenkin

    Research output: Contribution to journalArticlepeer-review


    A wide range of chemical and physical parameters has been observed over the course of a severe Europe-wide air pollution episode in August 2003. Detailed surface observations made at the rural perimeter edge of London, UK, indicated significantly elevated levels of primary volatile organic compounds (VOCs), ozone (>110 ppbV), other photochemical by-products such as PAN, HCHO, and oxygenates but not NOx. Reactive tracers in combination with Doppler wind radar and back trajectories have been used to establish that initial morning rises in O3 during the episode were caused by entrainment of air from aloft, polluted on regional scales from mainland Europe. Total VOC reactivity to OH approximately doubled during this episode, with similar distribution between functional groups, but showing a temperature dependent contribution from biogenic isoprene (maximum 1.2 ppbv). Under episodic conditions total peroxy radicals in excess of 60 pptv were observed in late afternoon with strong correlation to a later and higher peak in ozone. Episodic alkyl peroxy radicals were calculated to be substantially influenced by peroxy acetyl, via the thermal dissociation of PAN at high temperatures. © 2006 Elsevier Ltd. All rights reserved.
    Original languageEnglish
    Pages (from-to)7598-7613
    Number of pages15
    JournalAtmospheric Environment
    Issue number39
    Publication statusPublished - Dec 2006


    • Air quality
    • Isoprene
    • Non-methane hydrocarbons
    • Ozone
    • Pan
    • Peroxyradicals
    • Regional transport


    Dive into the research topics of 'Ozone photochemistry and elevated isoprene during the UK heatwave of august 2003'. Together they form a unique fingerprint.

    Cite this