AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
High-spatial Resolution Profiling of Aerosol Size Distribution Aloft a Highway
VERONIKA DOCEKALOVA, Jan Hovorka, Filip Kobrzek, Petr Marecek, Jan Bendl, Charles University in Prague
Abstract Number: 584 Working Group: Urban Aerosols
Abstract Dispersal of aerosol particles from specific sources within atmospheric boundary layer is usually calculated from earthbound measurements. Therefore, we conducted airborne measurements to experimentally determine spatial variability of number size distributions of atmospheric aerosol aloft a busy highway. Unmanned airship, remotely controlled with GPS 10Hz position tracking, electrically powered with propulsion vectoring and average cruising speed of 4 ms^-1, was used. The airship manoeuvrability allows data localisation within 5m both vertically and horizontally but depends on wind speed and strength of thermal vertical motion. Therefore, airship measurements were conducted from early morning to about midday for two days in June 2014 above the D1 highway SE of Prague (Czech Republic). There was a traffic flow from 4500 up to 7500 cars per hour at the D1 during the measurements. The airship carried temperature sensor and a TSI’s NanoScan SMPS and an Optical Particle Counter - OPC. Each monitor was connected to a separate heated inlet. First, longitudinal flights aloft a highway and nearby field situated up-wind were conducted with 60s integration time at heights from 40 to 200m. Two modes at 15 and 30nm were clearly distinguishable in the NanoScan size spectra with normalised PNC in the range of 10-6200cm^-3 varying significantly with a flight height. Second, transversal flights aloft the highway with data acquisition frequency of 1Hz for 15nm particle sizes and for the OPC full size range were conducted at height from 40-200m. Vertical profiles aloft a highway for various particle sizes were constructed.
The study was supported by project GA UK No. 1354314 of the Charles University in Prague.