Parameterization of new particle formation and growth at the Preila station

Abstract

The aerosol formation and subsequent particle growth in the ambient air have been observed at Preila station located in the coastal/marine environment. Submicron aerosol particle number concentrations and size distributions have been measured using a differential mobility particle sizer (ELAS-5Mc). The studied period covers June, July, and August 1997, June 2000, May 2001, and March, June, July, August, September, and October 2002. In this work, we related the nucleation events to atmospheric circulation and local meteorological parameters. Air mass backward trajectories were used to estimate the prehistory of sampled air. Moreover, trace gas (O3, NOx, and SO2) concentrations were analysed. The observed nucleation mode growth, the source rate of condensable material, and the changes of hygroscopic properties during the nucleation and growth events were analysed. The new particle formation rate, condensation and coagulation sinks were calculated. The growth rates varied between 1.2 and 9.9 nm/h. The formation rate was 0.14 cms. Such a low value of the formation rate could explain why in Preila there are so few event days. The median condensation sink was 1.5·10 s, and the vapour source rate was 8.06·10 cms.