Atmos. Chem. Phys. Discuss., 13, 14297-14330, 2013
© Author(s) 2013. This work is distributed
under the Creative Commons Attribution 3.0 License.
Review Status
This discussion paper has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP.
Hygroscopic properties of the Paris urban aerosol in relation to its chemical composition
K. A. Kamilli1,*, L. Poulain1, A. Held1,*, A. Nowak1,**, W. Birmili1, and A. Wiedensohler1
1Leibniz-Institute for Tropospheric Research, Leipzig, Germany
*now at: University of Bayreuth, Bayreuth Center of Ecology and Environmental Research, Bayreuth, Germany
**now at: Physikalisch-Technische Bundesanstalt, Braunschweig, Germany

Abstract. Aerosol hygroscopic growth factors and chemical properties were measured as part of the MEGAPOLI "Megacities Plume Case Study" at the urban site LHVP in the city center of Paris from June to August 2009, and from January to February 2010. Descriptive hygroscopic growth factors (DGF) were derived in the diameter range from 25 to 350 nm at relative humidities of 30, 55, 75, and 90% by applying the summation method on humidified and dry aerosol size distributions measured simultaneously with a humidified differential mobility particle sizer (HDMPS) and a twin differential mobility particle sizer (TDMPS). For 90% relative humidity, the DGF varied from 1.06 to 1.46 in summer, and from 1.06 to 1.66 in winter. Temporal variations in the observed mean DGF could be well explained with a simple growth model based on the aerosol chemical composition measured by aerosol mass spectrometry (AMS) and black carbon photometry (MAAP). In particular, good agreement was observed when sulfate was the predominant inorganic factor. A clear overestimation of the predicted growth factor was found when the nitrate mass concentration exceeded values of 10 μg m3, e.g. during winter.

Citation: Kamilli, K. A., Poulain, L., Held, A., Nowak, A., Birmili, W., and Wiedensohler, A.: Hygroscopic properties of the Paris urban aerosol in relation to its chemical composition, Atmos. Chem. Phys. Discuss., 13, 14297-14330, doi:10.5194/acpd-13-14297-2013, 2013.
Search ACPD
Discussion Paper
    Final Revised Paper