Abstract:
Ozone in the lower layer of the earth's atmosphere, the troposphere, is considered harmful to plants and human health. The surface ozone levels are determined by the strengths of sources and precursor emissions, and by the meteorological conditions. EPA has imposed regulations to encourage practices that restrict the production of ozone and has for many years monitored ozone concentration levels across the USA. Whether these regulations have effectively reduced ozone levels is in question because assessing the ozone trends is complicated by meteorological variability. In this report, a semiparametric modeling technique is used to build models which use meteorology to predict ozone levels. This technique can be used to estimate that part of the trend in ozone levels that cannot be accounted for by meteorology. The indications are that there is a decrease in ozone levels once the meteorological effects on ozone have been adjusted for. The models based on this technique are also shown to provide predictions which closely match the actual ozone levels. The results complement those of Bloomfield, Royle and Yang (1993) which produces similar conclusions.
Keywords:
Ozone concentration, meteorological adjustment, semiparametric regression.
tr14.pdf