Abstract：Ozone concentration and their frequency distributions were analyzed among different function areas in Shanghai based on measurements of ozone (O3), particulate matter (PM1, PM2.5, PM10), aerosol particle size distribution and meteorological parameters. With observations from tmospheric composition and meteorological sites, the study was focused on the period exceeding ozone standard between year 2011~2013. Summer photochemical pollution was very serious in Shanghai. Ozone pollution occured significantly more often in the suburban area than the central urban area. Photochemical pollution showed different patterns in different function areas, with more serious conditions at Jinshan chemical district and Chongming Island. Through analysis of aerosol variations before and after photochemical pollutionevents, aerosol concentrations, especially PM increased significantly. PM1/PM2.5 ratios during the pollution episodes were also significantly higher than during clean days, indicating that secondary aerosols increased significantly with the enhancement of photochemical reaction. Therefore, PM1 could be used as an important parameter to evaluate photochemical pollution.
