Diurnal and seasonal patterns of fluorescent bioaerosol and meteorological parameters in Bucharest, Romania

Pollen concentrations present in the atmosphere can raise serious human health problems, which is why they require studies with a higher precision and temporal resolution. The weather condition can produce direct changes in the growth and development of plants leading to changes in pollen concentrations or even changes in the pollen seasonal characteristics. This research was carried out on fluorescent bioaerosol concentrations obtained with the particle counter Rapid-E instrument that allows automatic collection. Fluorescent bioaerosol data were collected as hourly counts in the period 2018-2021 for the Bucharest-Magurele and were divided into three categories depending on the size of the particle diameter, namely small fluorescent particles (SF, particles less than 10 micrometers), large fluorescent particles (BF, greater than 10 micrometers) and, respectively, the total of fluorescent particles TF=SF+BF. In this research, diurnal variations of fluorescent bioaerosol concentrations as well as of temperature, relative humidity, wind speed and the height of the planetary boundary layer were studied. Hourly meteorological parameters were extracted from ECMWF global reanalysis ERA5 dataset from the Climate Change Service Copernicus platform. The multi-monthly averages and seasonal variations were also emphasized and local specificities were underlined. Statistical analyzes and graphical representations were performed using R software with the Openair package. Key words: bioaerosol, pollen, allergens, meteorology, aerobiology, East Europe