Transport and Ultrafine Particles: Source Apportionment Across Europe

Ultrafine particles (UFPs) are a critical component of urban air pollution, with potentially significant implications for public health due to their ability to translocate to different organs in the human body. Transportation remains a dominant source of  UFPs. This study investigates the contribution of various emission sources, with a particular focus on transportation, to UFP concentrations across Europe. The results provide insight into spatial and seasonal variability of UFP sources, with detailed analyses for Barcelona, Paris, and Athens.

PMCAMx-UF simulates both the number and mass distributions of atmospheric aerosols (Fountoukis et al., 2012). It incorporates processes such as horizontal and vertical advection, dispersion, wet and dry deposition, nucleation, coagulation, and gas-phase chemistry. The Posner and Pandis (2015) zero-out source apportionment methodology was applied using PMCAMx-UF for January and July 2019, with a 36 x 36 km grid resolution for Europe and 1 x 1 km for each city studied.

Our simulations highlight the significant contribution of transportation to UFP concentrations, with notable seasonal and spatial variations.  The PMCAMx-UF model’s predictions were compared with air quality monitoring data, demonstrating an overall good performance with some notable underprediction of N₁₀ concentrations in certain urban areas.

 

Fountoukis, C., Riipinen, I., Van Der Gon, H. D., Charalampidis, P. E., Pilinis, C., Wiedensohler, A., O’Dowd, C., Putaud, J. P., Moerman, M., & Pandis, S. N. (2012). Simulating ultrafine particle formation in Europe using a regional CTM: contribution of primary emissions versus secondary formation to aerosol number concentrations. Atmospheric Chemistry and Physics, 12(18), 8663–8677.

Posner, L. N., & Pandis, S. N. (2015b). Sources of ultrafine particles in the Eastern United States. Atmospheric Environment, 111, 103–112. https://doi.org/10.1016/j.atmosenv.2015.03.033