An Investigation of Pollutant Source Strength-Rainfall Relationships at St. Louis

Abstract

Speculation concerning effects of pollutants on weather, especially rainfall, has intrigued scientists and laymen alike in recent years. Results from Project METROMEX suggest that rainfall is increased after a moving raincell intersects the urban plume. This paper investigates correlations between rainfall and indices of aerosol pollutant source strength to see whether a causative mechanism might be suggested. Although the correlations between rainfall in certain areas and the source strength of three groups of urban aerosols are significant enough to warrant further investigation, physical relationships do not support an aerosol involvement in the urban rainfall anomaly.