Does lightning actually rise up from the earth?
Bob Kozlik, Riverwoods
It can. However, the great majority of ground lighting strikes involve the flow of electric current from cloud to ground. The installation of a nationwide lightning detection network in the early 1990s enabled researchers like Ron Holle to count lightning bolts accurately.
In the United States, the tally is 100 million to 125 million bolts annually, of which about 25 million are ground strikes. Of those, 90% are “negative,” meaning the flow of electric current is from cloud to ground.
The remaining 10% are “positive,” meaning the electric current flows from ground to cloud.