12,000

We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK

93%

93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Fluxes and concentrations of volatile organic c...
View graph of relations

« Back

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

Research output: Contribution to journalJournal article

Published

Journal publication date2010
JournalAtmospheric Chemistry and Physics
Journal number2
Volume10
Number of pages19
Pages627-645
Original languageEnglish

Abstract

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 C-2-benzenes). 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 degrees C it is estimated that more than half the isoprene observed in central London is of biogenic origin.