Ambient ozone patterns and effects over the Sierra Nevada: Synthesis and implications for future research

Abstract

Spatially explicit estimates of ambient ozone (O3) exposure to the Sierra Nevada were developed using data from an extensive survey of passive O3 monitors. The unique data set generated from the passive monitor network elicited widespread interest. As a result, three analysts were given the data set to develop relationships and estimate spatial and temporal patterns of ambient O3 for the Sierra Nevada. Spatial models of biweekly and seasonal O3 distribution were constructed by each group using topographical, weather, and other information. The results of these studies suggest that most of the Sierra Nevada study area was reliably estimated, although the distribution of the measurement sites could still be improved (there was clearly an insufficient number of sites on the eastern side of the mountain range). Along with monitoring ambient O3, evaluations of crown injury were performed at selected sites. The number of sites sampled for this study was low, and the distribution of the sample sites did not represent the distribution of the pines. In spite of these deficiencies, patterns of O3 injury generally followed patterns of O3 exposure risk.