Observation of new particle formation on Curonian Spit located between continental Europe and Scandinavia

Abstract

This study presents results of the research on atmospheric aerosol particles in the coastal environment, focusing on the investigation of new particle formation (NPF) events. Continuous measurements of the particle number size distribution (8.7–840nm) were performed at the Preila station throughout the year 2013. An estimation of the aerosol particle number concentration (PNC) of nucleation (8.7–20nm), Aitken (20–100nm) and accumulation modes (100–840nm) and their input to the total PNC were performed. The annual average value of the total PNC was 3.9·103cm−3. The seasonal variations of the total PNC essentially comprised the maximum monthly average in March (6.3·103cm−3) and the minimum in November (1.9·103cm−3). The highest input (44–64%) into the total PNC was influenced by Aitken mode particles. The particles of the accumulation mode made up 23% of the total PNC during spring, summer and autumn months, and comprised about 48% during winter months. The monthly average input of the nucleation mode particles to the total PNC varied from 11% to 20%. However, the diurnal average input of each nucleation mode particles to the total PNC had higher variations and showed the limits of the nucleation mode input to the total PNC depending on the inputs of Aitken and accumulation modes. It should be noted that the described limits of the nucleation mode input to the total PNC were constant for NPF event days and non-event day׳s datasets. During whole 2013 year were observed 111 NPF events, which were classified as Class I (18 days) and Class II (93 days). The average particle formation and growth rates were 0.45cm−3s−1 and 3.7nmh−1, respectively. The average condensation sink was 1.53·10−3s−1. The highest number of NPF days was observed when the air masses advected from northern directions (Scandinavia, the North Sea, and the Arctic) and contrary the NPF events were observed very rarely during advection of polluted continental air masses. Thus, the parameters estimated for the NPF events observed at the Preila station are partially similar to the Northern Europe stations. However, the PNC level, low seasonal PNC cycle and heterogeneous air masses showed similarity with Central Europe aerosol.