EVALUATION OF THE IMPACT OF EMISSION SOURCES IN CORPUS CHRISTI ON THE REGIONAL AIR QUALITY

摘要

Tropospheric ozone is a serious air pollution problem currently affecting many parts of the world including the United States as high ozone concentration damages human health, vegetation and also many common materials we use. Ozone is produced in the atmosphere through" a series of reactions involving precursors of ozone namely, oxides of nitrogen and volatile organic compounds (VOCs), which are emitted from various sources, such as, industries, motor vehicles, etc. Since the formation of ozone requires some time, very often high levels of ozone are formed at a place far-off from the source of emissions of ozone precursors, where they have been transported by wind. Corpus Christi is an industrialized urban area located in the semi-arid coastal region of South Texas. There is a concern in the neighboring areas of San Antonio and Austin that the emissions from Corpus Christi might be impacting the observed ozone levels in these areas adversely. Therefore, a photochemical modeling study was undertaken to evaluate the impact of Corpus Christi emission sources on the nearby areas of San Antonio and Austin. CAMx ver. 3.01, a photochemical model developed by ENVIRON (2000) was used for this purpose. We have selected the period of July 7-12, 1995 for this modeling study as high ozone levels were observed in San Antonio and Austin during this period and though Corpus Christi didn't observe high levels this episode was considered to be a good one from the point of view of evaluating ozone and precursor transport from Corpus Christi to San Antonio and Austin.