A case-study of fine particle concentrations and fluxes measured in a busy street canyon in Manchester, UK

Results are presented from the Street Canyon Aerosol Research experiment conducted in a canyon with busy one-way traffic in central Manchester, UK. Two Active Scattering Aerosol Spectrometer Probes were used, which were operated in conjunction with ultrasonic anemometers as eddy covariance systems. Results show that fine-mode particle number concentrations in the accumulation-mode size range were not acutely dependent upon wind direction. On most occasions, concentrations were inversely dependent upon wind speed. The concentrations of accumulation-mode particles followed a diurnal pattern characterized by a daily peak in the morning, a lesser peak during the evening, a plateau during lake morning and afternoon, and a minimum in the pre-dawn period. The emission velocity for fine particles exhibited a clear diurnal cycle, peaking at noon.