Meteorological Factors Affecting Particulate Air Pollution of a City
Due to its utility in handling joint functions, the method of coaxial graphical correlation is used to relate particulate air pollution at Nashville, Tennessee to various meteorological factors. The derived relationship applied to test data yielded an average absolute error of 38.3 micrograms per cubic meter and root-mean-square error of 59.3; these results are clearly superior to a climatological control forecast using seasonal average concentrations. Graphical analysis and supporting correlation-ratio computations suggest that small amounts of precipitation may be very effective in cleansing particulate matter from the atmosphere, rendering further precipitation of little consequence. The analysis emphasizes the importance of wind direction in governing air-pollution concentrations at a point, suggesting that point measurement of particulate concentrations may have little representativeness when applied to an area the size of a city. Particulate-matter concentration is found significantly correlated with day of the week (weekday-weekend groupings), offering an avenue for improvement of results.