Description of the Gulf States Ozone Monitoring Network and Decomposition into Subnetworks (1994)

Abstract:

We describe a 118 station Gulf States ozone monitoring networlc and de­compose this networlc into five spatially cohesive subnetworlcs using rotated principal components analysis. We provide empirical justification for this particular decomposition and perform some preliminary analyses of ozone in each of the subregions. Unadjusted (for meteorology) trends in networlc average maximum ozone among the subregions are different, ranging from nearly no trend in the "Louisiana" subregion to -17% / decade in the "Hous­ton" subregion. The standard errors of the estimated trends are homogeneous across subregions and we suggest a model for ozone under which this may further justify our subnetworlc specification. Estimated trends in the networlc maxima for each of the subregions produces results somewhat different than the analysis on the networlc average maxima. Future modeling worlc (e.g. meteorological adjustment of ozone) will primarily focus on ozone from these individual subnetworlcs. 

Keywords:

Ozone trends, Spatial sampling, Principal components anal­ysis.