Surface ozone during a winter when coal fired heat was used in the urban area of Jinan, China

Near surface ozone, NO, N02, and solar radiation levels were measured during late 2003 and early 2004, in the urban area of Jinan, China. Ozone levels were relatively low throughout the study period, while NOx were relatively high compared with other cities in the world. Statistical analysis of ozone showed a typical diurnal variation pattern of urban areas in Jinan, with the maximum in the afternoon and minimum in the early morning before sunrise. Analysis of ozone levels and solar radiation data in the daytime 8 h (08:00-16:00) shows that the variation of ozone follows solar radiation with a delay of about two hours, with both showing similar behavior. Further studies indicate that solar radiation is a significant impact factor for the daytime variations of ozone concentrations in Jinan, especially in the morning hours. Regression analysis of ozone level and N02/N0 concentration ratio shows that they correlated well with each other. In late winter and early spring days local effects play a major role in determining ozone concentrations in Jinan.