Study on optimum condition for photochemical ozone production caused by non-methane hydrocarbons emitted by vegetation in the polluted air

为了研究植被释放的NMHCs对城市污染空气中臭氧光化学生成的贡献，构建了臭氧光化学生成不可或缺的NMHCs （C_2-C_<10>）的自动连续测量系统。从去年12月开始对NMHC进行连续测量，特别关注异戊二烯、α-蒎烯和β-蒎烯浓度的季节性变化，以及这些气体占总NMHC的比例。同时，还建立了臭氧、氮氧化物（NO、NO_2）和太阳辐射（太阳总辐射、紫外线A和B）的测量。这些数据被记录在个人电脑中，以便进行各种分析。在此基础上，研究了臭氧及其前体物质的季节变化，并探讨了臭氧白天增加与臭氧前体物质（NMHCs、NO_X）浓度的关系。此外，还研究了生物源性NMHC对总NMHC的相对贡献。由于整个系统是在去年12月才准备好进行连续观测的，因此还没有获得足够的数据来讨论这些问题。这些测量正在进行中，并将采用光化学盒模型方法，包括观测数据，以研究生物源NMHCs对臭氧光化学产生的相对贡献。

In order to investigate the contribution of NMHCs emitted by vegetation to photochemical production of ozone in the polluted urban air, automatic continuous measurement system for NMHCs (C_2-C_<10>) which are indispensable for photochemical production of ozone was constructed. Continuous measurement of NMHCs was set up from last December particularly focusing on the seasonal variations in concentrations of isoprene, α-pinene and β-pinene, and fraction of these gases to the total NMHC. In parallel, measurements of ozone, nitrogen oxides (NO, NO_2) and solar radiation (global solar radiation, ultra violet A and B) were also set up at the same time. These data were recorded in the personal computer to enable to manipulate various analyses.Based on the analysis of these data sets, seasonal variations both in ozone and its precursors were investigated, and relationship between the daytime increase of ozone and concentrations of precursors of ozone (NMHCs, NO_X) was explored. In addition, relative contribution of biogenic NMHCs to total NMHC was also studied.Since it was last December that whole system was ready for continuous observation, enough data has not yet been obtained to discuss these issues. These measurements are going on, and photochemical box model approach will be carried out including observed data to study the relative contribution of biogenic NMHCs to the photochemical production of ozone.