Roadside Measurements of Traffic Emissions from Motorway BAB 656 in Heidelberg with Emphasis on Particles

摘要

The measurements showed some general features. If the wind direction was perpendicular to the motorway coming from southwest and the wind speed was low, highest particle concentrations in all three heights were observed. Southwest wind and high wind speed led to a vertical gradient with decreasing particle concentration from ground to 30m level, whereas a vertical gradient was negligible during northeast wind and low particle concentrations, indicating a well mixed background air mass. NO_x concentrations and to somewhat lesser degree CO showed a good correlation with particle number concentration. The best correlations between particle number / NO_x and particle number / CO where observed during southwest wind and wind speeds lower than 2 m/s. The background concentration varies with wind direction and wind speed from day to day.