【摘要】 为探索成都市PM_2.5污染物的空间来源及其演化机制,该文首先应用后向轨迹模型对灰霾期间抵达成都市的大气气团进行模拟,结果显示灰霾期间本地气团对成都市PM_2.5污染物的贡献远超过中远距离的外来气团,占比高达90%以上,局地空间内处于一种静稳状态。其次应用多重分形消除趋势波动分析法对灰霾期间PM_2.5的浓度序列进行多重分形分析,研究表明成都市灰霾期间PM_2.5浓度具有多重分形特征。最后运用相位随机替代法与随机重构法,对静稳条件下导致PM_2.5浓度多重分形特征的原因进行分析。结果表明灰霾期间,长期持续性在PM_2.5演化过程中占据主导地位,进而认为此次灰霾期间PM_2.5演化的长期持续性是其主要的内在动力机制,此时成都市大气空间内各局部空间PM_2.5浓度在多种要素的相互作用下逐步发展为一种相互同步的、均衡的平衡态。更多还原

【Abstract】 In order to investigate the space source and the evolution mechanism of PM_2.5during a typical haze in Chengdu,the backward trajectory model was used to simulate air mass trajectories which arrived Chengdu during the haze.The results show that the mass air of local regions provided more PM_2.5than other places,with the proportion more than 90%,and the local space is in a static and stable state.Multifractal detrended fluctuation analysis method was used to research the multifractal of PM_2.5during the haze,and it was found that the PM_2.5shows multifractal characteristics.With the static and stable conditions the sources of multifractal characteristic were studied,through shuffling procedure and phase randomization procedure,it showed that multifractal characteristic of PM_2.5was due to long-term memory during the haze.Finally,the dynamic mechanism of PM_2.5which controlled by local mass air are discussed based on the long-term memory,and the PM_2.5in the local space of Chengdu gradually develops into a synchronous and balanced equilibrium state under the interaction of various elements.更多还原