Karyn Sandiford and some of her friends were enjoying a pleasant day at the beach in Lytham St. Annes, United Kingdom, when dark clouds suddenly started to gather. Before the group heard thunder, they felt a tingling sensation on their arms, and Sandiford states her hair began to stand on end.
Once she reached home, Sandiford researched similar events and realized she had a close call with something potentially very dangerous. Milliseconds before lightning strikes, negative ions come down toward the Earth. This causes a positive charge to reach upward from the ground – these positive charges are usually emitted from high points or metal objects and they are known as “positive streamers.”
When negative ions move down toward the ground from the cloud – a process called “stepped ladder” – they often pause and change direction in case they cannot find a path to meet with a positive streamer. This entire process can repeat up to 10,000 times in just 1/20th of a second. A lightning strike occurs only once a channel is established, and positive ions start moving through the channel — sometimes multiple times.
Sometimes, when people serve as positive streamers, they can get injured, even if the lighting strike happens to connect via a different channel.
About this event, Chris Vagasky, a meteorologist at Vaisala, said, “In incidents like this, there is a lot of electric charge in the atmosphere … I wouldn’t call these upward streamers, per se, as those occur when the stepped leader is approaching the ground.”
About eight weeks before Sandiford had this close call at the beach, a 9-year-old was killed after being struck by lightning on a soccer field that is located just 2 miles away from the beach.
