Regional effect on urban atmospheric nucleation

Imre Salma, Zoltán Németh, Veli Matti Kerminen, Pasi Aalto, Tuomo Nieminen, Tamás Weidinger, Ágnes Molnár, Kornélia Imre, Markku Kulmala

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22 Citations (Scopus)


Secondary aerosol particle production via new particle formation (NPF) has been shown to be a major contributor to the global aerosol load. NPF has also been observed frequently in urban environments. Here, we investigate the effect of regional NPF on urban aerosol load under well-defined atmospheric conditions. The Carpathian Basin, the largest orogenic basin in Europe, represents an excellent opportunity for exploring these interactions. Based on longterm observations, we revealed that NPF seen in a central large city of the basin (Budapest) and its regional background occur in a consistent and spatially coherent way as a result of a joint atmospheric phenomenon taking place on large horizontal scales. We found that NPF events at the urban site are usually delayed by >1 h relative to the rural site or even inhibited above a critical condensational sink level. The urban processes require higher formation rates and growth rates to be realized, by mean factors of 2 and 1.6, respectively, than the regional events. Regional-and urban-type NPF events sometimes occur jointly with multiple onsets, while they often exhibit dynamic and timing properties which are different for these two event types.

Original languageEnglish
Pages (from-to)8715-8728
Number of pages14
JournalAtmospheric Chemistry and Physics
Issue number14
Publication statusPublished - Jul 18 2016


ASJC Scopus subject areas

  • Atmospheric Science

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