Apr
21
2012

Physics & Dynamics of Lightning

An article by Adrian Howard

Overview of Lightning

Lightning is one of nature’s dangerous phenomena that occur mainly from thunderstorms. Lightning can also occur in volcanic eruptions, with ash clouds as well. Knowing what to do during a lightning storm can potentially save your life and the lives of others as well. The physics of lightning dictate that it will seek out the tallest object in a location.

Each year numerous thunderstorms form around the world and also in the US that produce dangerous cloud to ground lightning, whether the lightning is frequent or steady from thunderstorms. As thunderstorms form, a process called electrification of clouds occurs. As small ice particles or soft hail and hailstones fall through a region of super cooled droplets and ice crystals, thunderstorm clouds become electrically charged. This is due to these particles rubbing together, as a result of rising motions or thunderstorm updrafts.

Thunderstorm clouds generally have positive charges, towards the upper-portions and anvil of the storm. Negative charges are generally found at the base of thunderstorms. At ground level, positive charges are generally found. With negative and positive charges, the physics of lightning dictate that the negative charges will want to meet up with the positive charges, because of the opposite attractions to each other. When this happens, a return charge and bright lightning flash that we see for a split second is created.

The higher up something is to the base of a thunderstorm, the easier there will be a lightning strike generated from a thunderstorm, because positive and negative charges are closer together. This is why it is not safe to be outside during a thunderstorm or open field at all. Neither is it safe to seek shelter under a tree during a thunderstorm. The safest place to be during a lightning storm is inside a building. Being outside or in open fields, near metal or close to a tree are not safe places and are lightning hotspots! So during this thunderstorm season, stay safe, we will keep you updated at Firsthand Weather.