大气光化学烟雾反应机理比较(Ⅰ)O_3和NO_x的比较

A COMPARISON OF ATMOSPHERIC PHOTOCHEMICAL MECHANISMS(Ⅰ) O_3 AND NO_x

在相同初始和排放条件下,对四种应用较广的光化学烟雾反应机理(ＣＢ４－９９,ＲＡＤＭ２,ＲＡＣＭ,ＳＡＰＲＣ９９)进行了比较．研究发现:对于Ｏ３,在低ＶＯＣＳ/ＮＯｘ时,四种机理模拟结果相关较小,平均相对标准偏差为７%,在高ＶＯＣＳ/ＮＯｘ时,平均相对标准偏差为２６%,差距较大;对于ＮＯｘ,多数情况下ＲＡＣＭ和ＲＡＤＭ２的模拟结果较高,ＣＢ４－９９和ＳＡＰＲＣ９９的模拟值偏低,其原因主要来源于不同机理中Ｏ３的生成对ＮＯｘ及ＶＯＣＳ的敏感性不同而造成的．在用模式模拟Ｏ３和ＮＯｘ时,应特别注意机理不同而带来的模拟结果差异．

A comparison of four atmospheric photochemical mechanisms (e.g. CB4-99, RACM, RADM2, SAPRC99) was conducted by using the same initial values and emission data. All mechanisms predicted O3 concentrations with minor differences in low VOCs/NOx ratios, and the mean RMS error in these cases is 7% . While in scenarios with high VOCs/NOx ratios, notable differences in O3 concentrations are found and the mean RMS errors is 26%. In most cases, RACM and RADM2 predicted higher concentrations of NOx than those by CB4-99 and SAPRC99. The reasons lie in the different sensitivities of O3 production with respect to NOx or VOCs in different mechanisms. Therefore, for selecting mechanisms in simulating of O3 and NOx, it should be paid more attention to the difference of these photochemical mechanisms.