Air Pollution Patterns in an Urban Street Canyon

High concentrations of carbon monoxide in an urban street canyon are known to accompany periods of slight atmospheric dispersion. It is found that during such episodes, certain individual or combined micrometeorological and source variables dominate the interaction during certain time segments of the day. For the early morning hours, the lapse rate can be used as a good predictor of the resultant CO concentration. Traffic count is the dominant variable than at all hours, except the early afternoon period when the wind speed is the most dominant. Model equations developed from statistical analysis of field data generalize to the three-dimensional air quality aspects of the particular urban roadway section studied and to those displaying similar characteristics and weather conditions.