A composite space/time approach to studying ozone distribution over Eastern United States

This work is concerned with the composite space/time analysis of ozone concentrations over Eastern U.S. A novel method is used, which introduces a mode of reasoning that is a fundamental combination of inductive and deductive processes. The method is based on a spatiotemporal random field that organizes information concerning ozone distribution by reference to a space/time continuum. Randomness manifests itself as an ensemble of realizations (possibilities, potentialities) regarding the ozone distribution. Random field representations can take several forms which can embody physical characteristics of the ozone distribution or transform the data into a form that has certain desirable features. Numerical applications of the composite space/time method show that it generates ozone estimates that are more accurate than the estimates obtained from purely spatial mapping methods; and it also leads to a technique of space/time ozone trend determination that performs better than mean filtering. Composite space/time ozone maps offer a means of gaining understanding and insight into the variation of ozone concentrations over the Eastern U.S. and are important tools in ascertaining compliance with ambient air quality standards. Theses maps are also the necessary inputs to ozone reliability studies and to ozone exposure-health damage analysis. (C) 1998 Elsevier Science Ltd. All rights reserved.