X-ray fluorescence spectrometry; synchrotron radiation; rotating drum impactor; positive matrix factorization; aerosol chemistry; source apportionment; atmospheric chemistry; trace elements; field measurements
Visser S., Slowik J. G., Furger M., Zotter P., Bukowiecki N., Canonaco F., Flechsig U., Appel K., Green D. C., Tremper A. H., Young D. E., Williams P. I., Allan J. D., Coe H., Williams L. R., Mohr C., Xu L., Ng N. L., Nemitz E., Barlow J. F., Halios C. H., Fleming Z. L., Baltensperger U., Prévôt A. S. H. (2015), Advanced source apportionment of size-resolved trace elements at multiple sites in London during winter, in Atmos. Chem. Phys.
, 15, 11291-11309.
Visser S., Slowik J. G., Furger M., Zotter P., Bukowiecki N., Dressler R., Flechsig U., Appel K., Green D. C., Tremper A. H., Young D. E., Williams P. I., Allan J. D., Herndon S. C., Williams L. R., Mohr C., Xu L., Ng N. L., Detournay A., Barlow J. F., Halios C. H., Fleming Z. L., Baltensperger U., Prévôt A. S. H. (2015), Kerb and urban increment of highly time-resolved trace elements in PM10, PM2.5 and PM1.0 winter aerosol in London during ClearfLo 2012, in Atmos. Chem. Phys.
, 15, 2367-2386.
Bohnenstengel S. I., Belcher S. E., Aiken A., Allan J. D., Allen G., Bacak A., Bannan T. J., Barlow J. F., Beddows D. C. S., Bloss W. J., Booth A. M., Chemel C., Coceal O., Di Marco C. F., Dubey M. K., Faloon K. H., Fleming Z. L., Furger M., Gietl J. K., Graves R. R., Green D. C., Grimmond C. S. B., Halios C. H., Hamilton J. F., Harrison R. M. (2015), Meteorology, air quality, and health in London: The ClearfLo project, in Bulletin of the American Meteorological Society
, 96(5), 779-804.
Bannan Thomas J., Booth A. Murray, Bacak Asan, Muller Jennifer B. A., Leather Kimberley E., Le Breton Michael, Jones Benjamin, Young Dominique, Coe Hugh, Allan James, Visser Suzanne, Slowik Jay G., Furger Markus, Prévôt André S. H., Lee James, Dunmore Rachel E., Hopkins James R., Hamilton Jacqueline F., Lewis Alastair C., Whalley Lisa K., Sharp Thomas, Stone Daniel, Heard Dwayne E., Fleming Zoë L., Leigh Roland (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, in Journal of Geophysical Research: Atmospheres
, 120, 5638-5657.
The identification of possible sources of ambient aerosols in metropolitan environments with the help of trace elements can be done with current statistical source apportionment methods based on factor analysis, like positive matrix factorization (PMF), and with meteorological trajectory modeling for the verification of geographic source areas. These methods will be applied to time series of elemental composition of aerosols sampled with three-stage rotating drum impactors in the field. The samples were analyzed with synchrotron radiation induced X-ray fluorescence spectrometry (SR-XRF). Significant progress has been achieved in recent years for the main aerosol constituents like organics, sulfates and nitrates, but further efforts are needed to refine our understanding of aerosol chemical and physical characteristics. A better understanding is a major prerequisite to develop optimum mitigation strategies to reduce negative environmental and health effects. Trace elements comprise a relatively small amount of the total aerosol mass. However, they are very well suited for source attribution and will refine the source apportionment based on other measurement techniques.We have analyzed ambient aerosol samples collected with time resolutions of 2 hours and segregated into three different size fractions (aerodynamic diameters 0.1-1.0, 1.0-2.5 and 2.5-10 micrometers). Samples have been collected during several integrated field campaigns in the past years (e.g. in Barcelona 2009, Paris 2009-2010, Los Angeles 2010, Marseille 2011), and in London in 2012. SR-XRF measurements for all samples have been successfully performed at synchrotron beamlines at SLS in Villigen, Switzerland, and at HASYLAB in Hamburg, Germany. The data is awaiting in-depth source apportionment and further analysis.The current grant has supported one PhD student who was responsible for performing field measurements in Marseille and London, and subsequently analyzing the collected samples of these and previous campaigns with SR-XRF and with source apportionment methods. Significant unanticipated difficulties in the calibration and quantification procedures of the spectral measurements have occurred, which ultimately have led to a delay in the current project. In this proposal we describe the research objectives for an additional 12 months of funding needed to complete the source apportionment part of the current project and to finalize the PhD thesis.