Figure 4
PM2.5 and CPM effects on visibility under haze (HZ), mist (BR), and fog (FG) from Model 6 for the ICN during the four years (2015–2018). The plots show the effect of a specific PM concentration decreases towards zero as the RH increases, with the effect of the PM2.5 on visibility significantly greater than that for the CPM. For fog, the effect of PM2.5 on visibility exhibits positive values (red arrow) at ZRH values > 1.5 (RH = 89%).
