大气光化学烟雾反应机理比较(Ⅰ)O3和NOx的比较

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 ATMOSPHERIC PHOTOCHEMICAL MECHANISMS(Ⅰ)O3 AND NOx

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.