What is a lightning flash?
According to IS/IEC 62305 Part-1, lightning flash can be defined as the discharge of charges between the cloud and the earth consisting of one or more strokes
Types of lightning discharges:
In general, there are four types of lightning discharges. The different types are shown in Figure 1.
1) Intra cloud discharges
2) Cloud to Cloud discharges
3) Cloud to Ground discharges and
4) Ground to Cloud discharges
Among these, more than 50% of the lightning flashes occur within the cloud and only the remaining flashes occur from cloud to ground.
Cloud to Ground discharge:
During 45% of cloud to ground flashes, the cloud is positively charged at the top, leaving negative charges at the bottom. So, the lightning starts as a negative leader from the cloud and discharges to the ground. In the remaining 5% flashes, the cloud to ground discharges is initiated as a positive leader from the cloud as the cloud is negatively charged at the top, leaving positive charges at the bottom.
Ground to Cloud discharge:
There are a few extremely rare flashes moving from ground to cloud, are found to occur in high mountain tops and man-made structures that are extremely tall.
Follow Us