The Effect of Corona Discharges on Droplets Settlement

To increase the ion density by corona discharge is an efficient way to generate charged nucleus from atmospheric aerosols and induce precipitation or eliminate fog. Here, we compare the brightness of discharge and optical emission spectrum (OES) of positive and negative corona discharges, and find the discharge intensity of the negative corona discharge is stronger than positive corona discharge at the same applied voltage. The combination of aerosols and more ions generated by negative corona discharges can produce numerous charged nucleus, which eventually generates large droplets and enhance precipitation through the short-range attractive force between charged nucleus and aerosols. The excessive condensation of water molecules on the negative electrode should be avoided for the application of large corona discharge systems in the mist-shrouded high mountains or airport.