Observation and Numerical Simulation on Volatile Organic Compounds in Urban Area

In this paper the spatial and temporal distribution characteristics of volatile organic compound (VOCs) are simulated and analyzed by using the urban air quality numerical prediction system and compared with the observation data. It is found that the concentration of VOC in Nanjing is higher in the winter than in the summer. The ratio of the concentration values in the winter case to those in the summer case is 1.24. The diurnal variation characteristics of the VOC concentrations are evident. There are two peak values at 0900 (LST) and 1700 (LST) respectively. The spatial distributions of the VOC are tightly related to many factors such as the positions of emission sources, surface wind fields etc. These research are beneficial to preventing and controlling the photochemical pollutions in urban area.