Climatology of Regional Ozone: Meteorologieal Effects on Ozone Exceedences in theSoutheast United States

摘要

A statistical anlysis of ozone (O3) concentrations and meterorogical parameterswas performed to determine the effect of meteorological changes on ambient O3 concentrations in the urban and semi-urban environment on a regional basis in the Southeast United States. The correlation between average daily maximum O3 concentration and various meteorological varibles was analyzed on a monthly basis from April through October 1980-1994. Positive correlation was found between O3 concentration and temperature and dewpoint temperature depression, while negative correlation was found between O3 concentration and relative humidity and the minimum Pasquill Stability Index. The correlations were strongest during the summer months, particularly June, July, and August. High pressure stagnation was found to be positively correlated with O3 concentrations, although not at a statistically significant level. Regional analysis indicates that the location of areas of high pressure stagnation may play an important role in the resultant ambient concentrations of O3 throughout the region. Analysis of long term O3 concentration trends indicates increasing trends during the 1980s and decreasing trends during the 1990s. Trends for meteorological parameters that demonstrate positive (negative) correlation with O3 increase(decrease) during the 1980s, however causal relationship between these trends and those for O3 cannot be determined based on this analysis. A regional model was developed to forecast ozone concentration based on the previous day's ozone concentration and meteorological parameters.