A Synthesis of Cloud Condensation Nuclei Counter (CCNC) Measurements within the EUCAARI Network.

0472900 - ÚCHP 2017 RIV DE eng J - Journal Article
Paramonov, M. - Kerminen, V.M. - Gysel, M. - Aalto, P.P. - Andreae, M.O. - Asmi, E. - Baltensperger, U. - Bougiatioti, A. - Brus, David - Frank, G.P. - Good, N. - Gunthe, S.S. - Hao, L. - Irwin, M. - Jaatinen, A. - Jurányi, Z. - King, S.M. - Kortelainen, A. - Kristensson, A. - Lihavainen, H. - Lohmann, U. - Martin, S.T. - McFiggans, G. - Mihalopoulos, N. - Nenes, A. - O'Dowd, C.D. - Ovadnevaite, J. - Petäjä, T. - Pöschl, U. - Roberts, G.C. - Rose, D. - Svenningsson, B. - Swietlicki, E. - Weingartner, E. - Whitehead, J. - Wiedensohler, A. - Wittbom, C. - Sierau, B.
A Synthesis of Cloud Condensation Nuclei Counter (CCNC) Measurements within the EUCAARI Network.
Atmospheric Chemistry and Physics. Roč. 15, č. 21 (2015), s. 12211-12229. ISSN 1680-7316. E-ISSN 1680-7324
EU Projects: European Commission(XE) 262254 - ACTRIS
Institutional support: RVO:67985858
Keywords : aerosol-chemical composition * size-resolved measurements * alpine site jungfraujoch
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 5.114, year: 2015

The annual mean ratio of activated cloud condensation nuclei (N-CCN) to the total number concentration of particles (N-CN), known as the activated fraction A, shows a similar functional dependence on supersaturation S at many locations - exceptions to this being certain marine locations, a free troposphere site and background sites in south-west Germany and northern Finland. The use of total number concentration of particles above 50 and 100 nm diameter when calculating the activated fractions (A(50) and A(100), respectively) renders a much more stable dependence of A on S; A(50) and A(100) also reveal the effect of the size distribution on CCN activation. With respect to chemical composition, it was found that the hygroscopicity of aerosol particles as a function of size differs among locations. The hygroscopicity parameter kappa decreased with an increasing size at a continental site in south-west Germany and fluctuated without any particular size dependence across the observed size range in the remote tropical North Atlantic and rural central Hungary. At all other locations kappa increased with size. In fact, in Hyytiala, Vavihill, Jungfraujoch and Pallas the difference in hygroscopicity between Aitken and accumulation mode aerosol was statistically significant at the 5% significance level. In a boreal environment the assumption of a size-independent kappa can lead to a potentially substantial overestimation of N-CCN at S levels above 0.6 %. The same is true for other locations where kappa was found to increase with size. While detailed information about aerosol hygroscopicity can significantly improve the prediction of N-CCN, total aerosol number concentration and aerosol size distribution remain more important parameters. The seasonal and diurnal patterns of CCN activation and hygroscopic properties vary among three long-term locations, highlighting the spatial and temporal variability of potential aerosol-cloud interactions in various environments.
Permanent Link: http://hdl.handle.net/11104/0270111