They are as terrifying as they are majestic. And as you gaze in awe of the stream of light ablaze from the sky above, your thought shortly after may be, “back away from the metal objects.” So as hypnotizing as this force of nature can be, you may even begin to wonder, what exactly goes into this electric force of nature? Allow us to break down the science behind that lightning display in the sky.
Starting by laying down a foundation for why you see what you see, you must first understand there is an electrical tension between the earth’s surface and the atmosphere. Our surroundings such as a tree, a car or even ourselves act as conductors. A tension starts to build between these opposing charges especially during cloud formations when these warm winds ascend to cooler temperatures in the atmosphere. The earth holds a negative charge where the outer atmosphere obtains a positively charged field.
These cloud formations cause a lot of activity in the opposing electrical charges, negative charges condenses at the bottom while the positive charges heap at the top of the cloud. The negative charge in the lower parts of the thunder cloud gain more force and starts to push away and separate itself from the earth’s negative force, clearing an area of positive charge between the cloud and the ground.
Tension between deferring charges finally reaches a boiling point and the time has come for that lustrous bolt that leaves you breathless. The negative charges at the bottom of the cloud form a negative channel, known as a leader, piercing through a normally resistant air to the earth, while the positive charge forms an opposing negative channel, known as a streamer, that moves up to meet it. This zip in energy conducts a surge of electricity when the leader and channel meet, traveling up/down both pathways.
So the next time you revel in that electric show in the sky, you know exactly what is going on behind the curtains (or clouds).
Images: Lightning: Nature and Culture