Characteristics of O3 and Precursors Concentrations in Hangzhou Urban Areas
杭州主城区O3与前体物浓度变化特征

Based on the air monitoring data in Hangzhou urban areas from 2004 to 2006, the concentrations of O_3 , NO_2 , CO, and their temporal variation characteristics were analyzed.The results showed that all the annual mean concentrations of O_3 , NO_2, and CO were low in the three years, which were 40, 60, and 1400 μg · m~(-3) , respec-tively. The concentrations of O_3 , NO_2 , and CO were different among seasons, O_3 concentration was the highest in summer and the lowest in winter, while both NO_2 and CO concentrations were higher in winter and lower m summer. The diurnal variations of the concentrations of O_3 , NO_2 , and CO were obvious, the diurnal variations of O_3 concentrations showed one peak, while the others had two peaks.The relationship between O_3 and hydrocarbons concentration in different weather conditions showed that O_3 concentration increased significantly and hydrocarbons reduced during cloudless days, but during cloudy days O_3 concentration was lower and hydrocarbons concentrations were higher, and their concentrations changed little In the daytime and nighttime, O_3 and C_2-C_(12) hydrocarbons concentrations changed with different wind velocity. In the daytime, the C_2-C_(12) hydrocarbons concentrations reduced with the increase of wind speed, and O_3 was exactly opposite.The similar situation was not found in the nighttime.