Simulating secondary organic aerosol from missing diesel-related intermediate volatility organic compound emissions during the Clean Air for London (ClearfLo) campaign

Riinu Ots, D. E. Young, Massimo Vieno, L. Xu, R. E. Dunmore, J. D. Allan, H. Coe, L. R. Williams, S. C. Herndon, N. L. Ng, J. F. Hamilton, R. Bergstöm, C.F. Di Marco, E. Nemitz, Ian MacKenzie, J. J. P. Kuenen, D.C. Green, Stefan Reis, Mathew R. Heal

Research output: Contribution to journalArticlepeer-review


We present high-resolution atmospheric chemistry transport model (ACTM) simulations of secondary organic aerosol (SOA) formation over the UK for 2012. Our simulations include additional diesel-related intermediate volatility organic compound (IVOC) emissions derived directly from comprehensive field measurements at an urban background site in London during the 2012 Clean Air for London (ClearfLo) campaign. Our IVOC emissions are added proportionally to VOC emissions, as opposed to proportionally to primary organic aerosol (POA) as has been done by previous ACTM studies seeking to simulate the effects of these missing emissions. Modelled concentrations are evaluated against hourly and daily measurements of organic aerosol (OA) components derived from aerosol mass spectrometer (AMS) measurements also made during the ClearfLo campaign at three sites in the London area. Good hourly performance in comparison to the measurements was shown, giving confidence in the SOA prediction skill of the ACTM system used.

According to the model simulations, diesel-related IVOCs can explain on average ~30% of the annual SOA in and around London. Furthermore, the 90-th percentile of modelled daily SOA concentrations for the whole year is 3.8 μg m−3 (more than 40% of which is produced from the missing diesel precursors), constituting a notable addition to total particulate matter. More measurements of these precursors (currently not included in official emissions inventories) is recommended.

During the period of concurrent measurements, SOA concentrations at the Detling rural background location east of London were greater than at the central London location. The model shows that this was caused by an intense pollution plume with a strong gradient of imported SOA passing over the rural location. This demonstrates the value of modelling for supporting the interpretation of measurements taken at different sites or for short durations.
Original languageEnglish
Article numberacp-16-6453-2016
Pages (from-to)6453-6473
Number of pages21
JournalAtmospheric Chemistry and Physics
Publication statusPublished - 18 Jan 2016


  • PM2.5
  • intermediate VOC
  • Air quality modelling
  • diesel vehicle emission
  • Air pollution monitoring
  • SOA
  • ClearfLo


Dive into the research topics of 'Simulating secondary organic aerosol from missing diesel-related intermediate volatility organic compound emissions during the Clean Air for London (ClearfLo) campaign'. Together they form a unique fingerprint.

Cite this