Defence of MSc thesis by Anja Petra Bencek / 28.10.2019

Anja Petra Bencek successfully defended her MSc thesis entitled "Nanoparticle concentrations in ambient air in relation to atmospheric stability", at the School of Environmental Sciences, University of Nova Gorica, on October 11, 2019.

The research based on continuous nanoparticle number concentration measurements (size range 10 – 1100 nm) in ambient air in Ljubljana using a ‘Scanning Mobility Particle Sizer’ device (Grimm Aerosol Technik) in yearly seasons of 2018. For nanoparticles, two groups have been considered, i.e., particles smaller than 0.1 µm (PM0.1) and bigger than 0.1 µm (PM1.1), and dependence of their number concentration on the atmospheric stability, which was determined on the basis of radon (222Rn) activity concentration, was observed. Also radon was measured continuously (frequency once an hour) using an ‘AlphaGuard’ monitor (Bertin Instruments) the entire year. Concentration of PM0.1 has shown a high correlation with traffic. It was markedly increasing with traffic density during workdays, and decreasing by approximately a half during weekends. The concentrations of PM0.1 were in a similar range throughout the year, showing large fluctuations within a single day. In contrast, PM1.1 concentration was less dependent on traffic and therefore, their diurnal changes are not so much pronounced. PM1.1 concentration follows changes in the atmospheric stability, thus generally increasing with increasing stability and vice versa. The highest PM1.1 concentration is during the persistent temperature invasion periods (autumn and winter). PM0.1 concentration has shown weaker relationship with atmospheric stability. More info (in Slovene) ...