ClearfLo at PSI

Duration: 2011-2014

Contact: André Prévôt, andre.prevot@psi.ch

The ClearfLo (Clean Air for London) Project is a collaborative scientific project involving several academic institutions in the UK and abroad, to set up air pollution monitoring sites alongside meteorological measurements to investigate boundary layer pollution across London. PSI contributes with highly time- and size-resolved measurements of trace elements (see also the XRF-PMF project), with measurements of 14-C in total carbon, elemental and organic carbon as well as Aethalometer measurements.
Sampling was performed at a site with heavy traffic (Marylebone Road) and at an urban background site (North Kensington) in London, and at a rural site in Detling, southeast of London in winter 2012. Summer sampling took place at the two London sites during a period which included the Olympic Games. Rotating drum impactors (RDIs) collected particles in three size bins (PM10-2.5, PM2.5-1.0 and PM1.0-0.3) with a high time resolution of 2 h. The elemental composition of the samples was analysed by synchrotron radiation-induced X-ray fluorescence spectrometry (SR-XRF) at the Swiss Light Source (SLS, Paul Scherrer Institute, CH) and at HASYLAB (Deutsches Elektronen-Synchrotron, DE).

More on the ClearfLo Project on the official ClearfLo website.

• 11 January to 08 February 2012 (3 sites: Marylebone Road, North Kensington, Detling)
• 18 July to 22 August 2012 (2 sites: Marylebone Road, North Kensington)

• The wood burning fractions in North Kensington and Detling as apportioned with the Aethalometer model are 15% ± 12% and 30% ± 13%, respectively.

• Total non-fossil fractions in North Kensington and Detling are 53% ± 6% and 64% ± 7%.

• Trace element concentrations are strongly influenced by local sources within London, with brake wear elements (e.g. Cu, Sb, Ba) showing the largest increase of up to 18x higher concentrations at Marylebone Road relative to North Kensington.

• Source apportionment on trace elements identifies sources found in all three size fractions such as traffic and sea salt, but also finds unique sources in a specific size fraction such as wood burning in the fine fraction and an industrial factor in the coarse fraction.

This work was funded by the ClearfLo project (NERC grant NE/H00324X/1), by the Swiss National Science Foundation (SNF grant 200021_132467/1) and by the European Community’s Seventh Framework Programme (FP7/2007-2013, grant n°312284).

Journal Articles

Sources and contributions of wood smoke during winter in London: assessing local and regional influences.
Crilley, L. R., W. J. Bloss, J. Yin, D. C. S. Beddows, R. M. Harrison, J. D. Allan, D. E. Young, M. Flynn, P. Williams, P. Zotter, A. S. H. Prevot, M. R. Heal, J. F. Barlow, C. H. Halios, J. D. Lee, S. Szidat, and C. Mohr, 2015
Atmos. Chem. Phys., 15, 3149-3171.
DOI: 10.5194/acp-15-3149-2015

Advanced source apportionment of size-resolved trace elements at multiple sites in London during winter.
Visser, S., J. G. Slowik, M. Furger, P. Zotter, N. Bukowiecki, F. Canonaco, U. Flechsig, K. Appel, D. C. Green, A. H. Tremper, D. E. Young, P. I. Williams, J. D. Allan, H. Coe, L. R. Williams, C. Mohr, L. Xu, N. L. Ng, E. Nemitz, J. F. Barlow, C. H. Halios, Z. L. Fleming, U. Baltensperger, and A. S. H. Prévôt, 2015
Atmos. Chem. Phys. Discuss., 15, 14733-14781.
DOI: 10.5194/acpd-15-14733-2015

The first UK measurements of nitryl chloride using a chemical ionization mass spectrometer in central London in the summer of 2012, and an investigation of the role of Cl atom oxidation.
Bannan, T. J., A. M. Booth, A. Bacak, J. B. A. Muller, K. E. Leather, M. Le Breton, B. Jones, D. Young, H. Coe, J. Allan, S. Visser, J. G. Slowik, M. Furger, A. S. H. Prévôt, J. Lee, R. E. Dunmore, J. R. Hopkins, J. F. Hamilton, A. C. Lewis, L. K. Whalley, T. Sharp, D. Stone, D. E. Heard, Z. L. Fleming, R. Leigh, D. E. Shallcross, and C. J. Percival, 2015
Journal of Geophysical Research: Atmospheres, 120, 5638-5657.
DOI: 10.1002/2014JD022629

Kerb and urban increment of highly time-resolved trace elements in PM10, PM2.5 and PM1.0 winter aerosol in London during ClearfLo 2012.
Visser, S., J. G. Slowik, M. Furger, P. Zotter, N. Bukowiecki, R. Dressler, U. Flechsig, K. Appel, D. C. Green, A. H. Tremper, D. E. Young, P. I. Williams, J. D. Allan, S. C. Herndon, L. R. Williams, C. Mohr, L. Xu, N. L. Ng, A. Detournay, J. F. Barlow, C. H. Halios, Z. L. Fleming, U. Baltensperger, and A. S. H. Prévôt, 2015
Atmos. Chem. Phys., 15, 2367-2386.
DOI: 10.5194/acp-15-2367-2015

Meteorology, air quality, and health in London: The ClearfLo project.
Bohnenstengel, S. I., S. E. Belcher, A. Aiken, J. D. Allan, G. Allen, A. Bacak, T. J. Bannan, J. F. Barlow, D. C. S. Beddows, W. J. Bloss, A. M. Booth, C. Chemel, O. Coceal, C. F. Di Marco, M. K. Dubey, K. H. Faloon, Z. L. Fleming, M. Furger, J. K. Gietl, R. R. Graves, D. C. Green, C. S. B. Grimmond, C. H. Halios, J. F. Hamilton, R. M. Harrison, M. R. Heal, D. E. Heard, C. Helfter, S. C. Herndon, R. E. Holmes, J. R. Hopkins, A. M. Jones, F. J. Kelly, S. Kotthaus, B. Langford, J. D. Lee, R. J. Leigh, A. C. Lewis, R. T. Lidster, F. D. Lopez-Hilfiker, J. B. McQuaid, C. Mohr, P. S. Monks, E. Nemitz, N. L. Ng, C. J. Percival, A. S. H. Prévôt, H. M. A. Ricketts, R. Sokhi, D. Stone, J. A. Thornton, A. H. Tremper, A. C. Valach, S. Visser, L. K. Whalley, L. R. Williams, L. Xu, D. E. Young, and P. Zotter, 2014
Bull. Amer. Meteor. Soc., 96, 779-804.
DOI: 10.1175/BAMS-D-12-00245.1

Contribution of Nitrated Phenols to Wood Burning Brown Carbon Light Absorption in Detling, United Kingdom during Winter Time.
Mohr, C., F. D. Lopez-Hilfiker, P. Zotter, A. S. H. Prévôt, L. Xu, N. L. Ng, S. C. Herndon, L. R. Williams, J. P. Franklin, M. S. Zahniser, D. R. Worsnop, W. B. Knighton, A. C. Aiken, K. J. Gorkowski, M. K. Dubey, J. D. Allan, and J. A. Thornton, 2013
Environmental Science & Technology, 47, 6316-6324.
DOI: 10.1021/es400683v

Size distribution, mixing state and source apportionments of black carbon aerosols in London during winter time.
Liu, D., J. D. Allan, D. E. Young, H. Coe, D. Beddows, Z. L. Fleming, M. J. Flynn, M. W. Gallagher, R. M. Harrison, J. Lee, A. S. H. Prevot, J. W. Taylor, J. Yin, P. I. Williams, and P. Zotter, 2014
Atmos. Chem. Phys. Discuss., 14, 16291-16349.
DOI: 10.5194/acpd-14-16291-2014

Thesis

Highly time- and size-resolved ambient trace element analysis and source apportionment.
Visser, S., 2015.
Diss. ETH No. 22520, Environmental Sciences, ETH Zürich.
DOI: 10.3929/ethz-a-010444260 - 12.26 MB

Conference Contributions

Measuring sodium concentrations in London winter aerosols with Synchrotron Radiation induced X-Ray Fluorescence Spectrometry.
Furger, M., S. Visser, C. Frieh, U. Flechsig, T. Huthwelker, C. Mohr, D. E. Young, J. D. Allan, D. Green, L. R. Williams, U. Baltensperger, and A. S. H. Prévôt, 2012.
EXRS 2012 - European Conference on X-ray Spectrometry, Vienna, Austria, 18-22 June 2012, Technische Universität Wien, Atominstitut, 271.

Highly time- and size-resolved measurements of trace elements in London during ClearfLo.
Visser, S., M. Furger, U. Flechsig, K. Appel, R. Dressler, P. Zotter, J.G. Slowik, A.S.H. Prevot, and U. Baltensperger, 2013.
EAC2013 - European Aerosol Conference 2013, Prague, Czeck Republic, 1-6 Sept 2013.

Highly time- and size-resolved measurements of trace elements in London during ClearfLo.
Visser, S., M. Furger, U. Flechsig, K. Appel, R. Dressler, P. Zotter, J.G. Slowik, A.S.H. Prevot, and U. Baltensperger, 2014.
9th International Conference on Air Quality - Science and application, Garmisch-Partenkirchen, Germany, 24-28 March 2014.

Trace element source apportionment in European and Asian megacities.
Visser, S., M. Furger, J.G. Slowik, K. Appel, F. Canonaco, J. Cao, M. Crippa, M. Elser, U. Flechsig, D. Green, K-F. Ho, R-J. Huang, L. Poulain, Q. Wang, R. Wolf, P. Zotter, U. Baltensperger, and A.S.H. Prevot, 2014.
IAC2014 - International Aerosol Conference 2014, Busan, Korea, 28 Aug-2 Sep 2014.

Black Carbon Containing Particles at a Rural Site Southeast of London, UK during ClearfLo (Winter 2012).
Williams, L. R., S. Herndon, J. Jayne, A. Freedman, B. Brooks, J. Franklin, P. Massoli, E. Fortner, P. Chhabra, M. Zahniser, T. Onasch, M. R. Canagaratna, D. R. Worsnop, F. Lopez-Hilfiker, C. Mohr, J. Thornton, N. L. Ng, L. Xu, W. B. Knighton, M. Dubey, A. Aiken, K. Gorkowski, S. Liu, S. Visser, M. Furger, P. Zotter, and A. S. H. Prévôt, 2013.
AAAR 32nd Annual Conference, Portland, OR, USA, 30 September - 4 October 2013.

Black Carbon Containing Particles at a Rural Site Southeast of London during ClearfLo Winter IOP.
Williams, L. R., S. Herndon, J. Jayne, A. Freedman, B. Brooks, J. Franklin, P. Massoli, E. Fortner, P. Chhabra, M. Zahniser, H. Stark, T. Onasch, M. R. Canagaratna, D. R. Worsnop, F. Lopez-Hilfiker, C. Mohr, J. Thornton, N. L. Ng, L. Xu, W. B. Knighton, M. Dubey, A. Aiken, K. Gorkowski, S. Liu, T. Martin, R. Coulter, S. Visser, M. Furger, P. Zotter, and A. S. H. Prévôt, 2013.
EAC - European Aerosol Conference 2013, Prague, Czech Republic, 1-5 Sep 2013.

Overview of ClearfLo: Study of Aerosol Sources and Processing at a Rural Site Southeast of London, January-February, 2012.
Williams, L. R., S. Herndon, J. Jayne, A. Freedman, B. Brooks, J. Franklin, P. Massoli, E. Fortner, P. Chhabra, M. Zahniser, H. Stark, T. Onasch, D. R. Worsnop, F. Lopez-Hilfiker, C. Mohr, J. Thornton, N. L. Ng, L. Xu, B. Knighton, M. Dubey, A. Aiken, K. Gorkowski, S. Liu, T. Martin, R. Coulter, S. Visser, M. Furger, P. Zotter, A. S. H. Prévôt, J. Allan, and D. Young, 2014.
ASR STM 2014, Potomac, Maryland, USA, 10 -13 March 2014.

Overview of ClearfLo: Study of Aerosol Sources and Processing at a Rural Site Southeast of London.
Williams, L. R., S. Herndon, J. Jayne, A. Freedman, W. Brooks, J. Franklin, P. Massoli, E. Fortner, P. Chhabra, M. Zahniser, H. Stark, T. Onasch, D. R. Worsnop, F. Lopez-Hilfiker, C. Mohr, J. Thornton, N. L. Ng, L. Xu, B. Knighton, M. Dubey, A. Aiken, K. Gorkowski, T. Martin, R. Coulter, S. Visser, M. Furger, P. Zotter, and A. S. H. Prévôt, 2013.
DOE Atmospheric System Research Science Team Meeting, Potomac, MD, USA, 18-21 March 2013.

Seasonal comparison of comprehensive aerosol measurements in London during CleafLo.
Young, D. E., J. D. Allan, P. I. Williams, M. J. Flynn, D. Liu, J. D. Whitehead, A. S. H. Prévôt, S. Visser, M. Furger, M. W. Gallagher, and H. Coe, 2012.
EAC - European Aerosol Conference 2012, Granada, Spain, 2-7 Sep 2012.

Seasonal comparison of comprehensive aerosol measurements in London during CleafLo.
Young, D. E., J. D. Allan, P. I. Williams, M. J. Flynn, D. Liu, J. D. Whitehead, N. Robinson, A. S. H. Prévôt, S. Visser, M. Furger, M. W. Gallagher, and H. Coe, 2012.
AAAR 31st Annual Conference, Minneapolis, Minnesota, USA, 8-12 October.