This investigation presents campaign-based results related to the influence of the mixing layer height, main meteorological parameters and urban environment on the vertical distribution of the aerosol particles obtained in July 2015 and July 2018.
Variations in the aerosol particle concentrations in space and time were measured by six-channel laser-based aerosol particle counters (LPCs) at three different altitudes: 577 m a.s.l. in the downtown of the city of Sofia (the Astronomical Observatory (AO) in the Borisova Gradina Park), 900 m and 1350 m on the northern slope of Vitosha Mountain during the first campaign. In the second campaign, two of the LPCs were replaced by different ones, capable of measuring both particle number and mass concentrations. An additional particle detector was included in the set of instruments in order to implement measurements of the particle mass concentrations at three altitudes.
The combined effect of the mixing layer height development (followed by a ceilometer, located at the AO), main meteorological parameters, and the intensity of the vehicle traffic on the variations in the concentrations of the different aerosol fractions in time and at the different sites of observations is considered and discussed.
Key words: particle number and mass concentrations, planetary boundary layer, laser particle counter, ceilometer
Topic: GEOPHYSICS