AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Dynamics of Nanoparticle Size Distribution in a Boundary Layer by an Airborne and Ground Measurements
JAN HOVORKA, Nikola Kuzelova, Cecilia Leoni, Jan Bendl, Oliver F. Bischof, Charles University in Prague
Abstract Number: 276 Working Group: Aerosol Physics
Abstract Diurnal variations of vertical profiles for number-size distributions and concentrations of aerosol nanoparticles in planetary boundary layer were measured and evaluated from ground and airborne measurement. One minute integrates of the aerosol distributions by nanoscan spectrometer positioned in an unmanned airship were compared with five minute distributions recorded on the ground. Airborne measurements were conducted at heights 20-500m (1000m) of winter planetary boundary layer of urban atmosphere aloft residential district of Kladno city, Czech Republic. Vertical size distribution profiles recorded above sports field in the residential district exhibited strong diurnal variation. While early morning profile recorded during strong temperature inversion indicated nanoparticle sources on the ground, increasing intensity of the Sun radiation during time of the day causes temperature inversion disappearance, decrease of PM1 mass and relative humidity, steep increase of ozone concentration. This conditions favor new particle formation at heights about 250-350m. Newly formed particles are then being transported downward by strongly evolved turbulence in planetary boundary layer and detected on the ground. This finding supports the hypothesis that new particle formation, frequently observed on the ground may, in fact, originate at elevated altitudes.
The study is supported by the Czech Grant Agency (P503/12/G147).