Variation of aerosol particle and its impact on pollution flashover events over Eastern China

The deposition of atmospheric particles on the insulator is one of the important causes for the pollution flashover events in the power grid. The distribution characteristics of atmospheric aerosol particle and its relationship with the flashover in the Eastern China are analyzed in this work. Firstly, the temporal and horizontal distributions of aerosol optical depth (AOD), Angstrom exponent (AE), fraction of fine-mode aerosol (FMF) and particle columnar mass concentration (CMC) are analyzed during 2003 to 2013 over Eastern China using MODIS Level 3 aerosol products. The distribution of AODs have a latitudinal distinction in this region, AOD is higher in the northern part (30°N north) than the southern part. The annual means of AOD are about 0.6-0.7 in the northern part and lower than 0.5 in the southern, respectively. The mean AODs of spring and summer are higher than those of autumn and winter, with the highest one in summer. It shows a fluctuant increasing trend of AOD in this region, which increases faster in the northern part than the southern. The AE has no significant variation in the research years. It presents a distribution of high in the southern part and low in the northern. It shows a seasonal feature of high in spring and winter and low in summer and autumn. The FMF of spring and winter is lower than that of summer and autumn. It shows lower FMFs in the northern part than the southern, while the growth rate of the northern is faster than the southern. To the CMC of aerosol, it shows higher value in the northern part, with the highest values in the region of Jiangsu and Shanghai and the lowest in Zhejiang. The highest CMC is in spring, while the lowest in autumn. It shows an increasing trend of CMC in the northern part, while decreasing in the southern.