VOC emission rates over London and South East England obtained by airborne eddy covariance

Adam R. Vaughan, James D. Lee*, Marvin D. Shaw, Pawel K. Misztal, Stefan Metzger, Massimo Vieno, Brian Davison, Thomas G. Karl, Lucy J. Carpenter, Alastair C. Lewis, Ruth M. Purvis, Allen H. Goldstein, C. Nicholas Hewitt

*Corresponding author for this work

Research output: Contribution to journalReview articlepeer-review

Abstract

Volatile organic compounds (VOCs) originate from a variety of sources, and play an intrinsic role in influencing air quality. Some VOCs, including benzene, are carcinogens and so directly affect human health, while others, such as isoprene, are very reactive in the atmosphere and play an important role in the formation of secondary pollutants such as ozone and particles. Here we report spatially-resolved measurements of the surface-to-atmosphere fluxes of VOCs across London and SE England made in 2013 and 2014. High-frequency 3-D wind velocities and VOC volume mixing ratios (made by proton transfer reaction-mass spectrometry) were obtained from a low-flying aircraft and used to calculate fluxes using the technique of eddy covariance. A footprint model was then used to quantify the flux contribution from the ground surface at spatial resolution of 100 m, averaged to 1 km. Measured fluxes of benzene over Greater London showed positive agreement with the UK's National Atmospheric Emissions Inventory, with the highest fluxes originating from central London. Comparison of MTBE and toluene fluxes suggest that petroleum evaporation is an important emission source of toluene in central London. Outside London, increased isoprene emissions were observed over wooded areas, at rates greater than those predicted by a UK regional application of the European Monitoring and Evaluation Programme model (EMEP4UK). This work demonstrates the applicability of the airborne eddy covariance method to the determination of anthropogenic and biogenic VOC fluxes and the possibility of validating emission inventories through measurements.

Original languageEnglish
Pages (from-to)599-620
Number of pages22
JournalFARADAY DISCUSSIONS
Volume200
Early online date3 Feb 2017
DOIs
Publication statusPublished - 3 Feb 2017

Bibliographical note

This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details

Cite this