A climatological examination and modeling of carbon monoxide concentrations in central Phoenix, Arizona

Abstract

This thesis examines the temporal characteristics and climatology of wintertime carbon monoxide (CO) concentrations in central Phoenix (AZ). Variations in CO concentrations on several temporal scales are explored to determine the relationship between atmospheric conditions, CO concentrations, and motor vehicle traffic levels as well as to spotlight the timing of high CO concentrations. Typical surface atmospheric conditions that are related to high and low CO mornings are revealed through compositing. Finally, a set of CO forecasting models are developed that predict 3 AM 8 hour average CO concentrations. Important results are as follows. The first three weeks of December have the most CO exceedance days. High CO concentrations are associated with anticyclonic conditions while low CO concentrations are linked to the passage of a cold front or trough. Final models had little systematic mean squared error and predictions that were within 1 ppm of the observed CO concentration.