A Research of Photochemical Transformation of NOx in Troposphere
对流层氮氧化物光化学转化特征研究

A study of primary controlling factors of NOX photochemical transformations during the daytime and NOX transformation products were conducted by using an atmospheric photochemical box model. The results show that the most important factors are radiant intensity and NMHC/ NOX ratio, however low NMHC/ NOX ratio, NOX transformation rate cannot increase remarkably with radiant intensity. The effect of temperature and initial ozone level on NOX transformation rate ranks seoonel, and the relative humidity effect is quiet small. Under different NMHC / NOX ratios, the NOX transformation features and products compositions are very different. For higher NMHC/ NOX ratio, the PAN level is higher than HNO3. In middle (lower) NMHC/ NOX ratio, the product is mainly composed of HNO3; however, PAN and other organic nitrogen compound are smaller than 10%(1%) of total NOy. Lastly, the modeling NOy compositions are compared with measurements in some areas.