成都市典型重度灰霾期间NO_2演化长期持续性特征的空间稳定性

应用消除趋势波动分析方法,研究了成都市一次典型重度灰霾期间,城区6个监测站点大气NO2小时平均浓度序列的时空演化尺度特征.研究表明,尽管在灰霾期间成都市各站点NO2浓度波动在空间上差异很大,但NO2演化动态在5 d的宏观时间尺度上表现出很强的长期持续特征,且各站点的差异性不大,在空间上具有稳定性.该特征表明,成都市灰霾期间某一时刻所排放的NO2将持续地对未来5 d的NO2浓度带来影响,成都市灰霾期间NO2的波动演化在动力学上主要是由NO2的长期持续性特征主导控制.研究结果有助于进一步加强对灰霾期间大气NO2污染演化复杂规律的认识.

Space Stability of Long-term Persistence Characteristics of NO2 during Typical Severe Haze Episode in Chengdu

The temporal scaling properties and long-term persistence of the hourly NO2 average concentration series are investigated by applying the detrended fluctuation analysis method during a typical haze episode in Chengdu, China. The average concentrations of NO2 are obtained from the China National Environ-mental Monitoring Centre. In this study, there are eight automatic monitoring stations in Chengdu city. Because of the missing data, only six stations are examined. The results show that the evolution of NO2 concen-trations is characterized by power-law distribution, and the spatial and temporal sealing behaviors exhibit scale-invariant and long-term persistence. The long-term persistence has stable characteristics during the haze episode. We suggest that the temporal evolution of NO2 concentrations is mainly affected by the long- term persistence mechanism. Under the influence of the mechanism, more consideration should be taken in the temporal sealing properties and the long-term persistence characteristics of the evolution of NO2. This study helps to further strengthen understanding of the NO2 pollution evolution process during the haze episode.