Transcript:

music; ambience: filling balloon; lightning

Okay, you ready to fill. Let me, let me go check the gauge” [blast of air]

Welcome to Pulse of the Planet’s Science Diaries, a glimpse of the world of science from the inside. This month, a look back at some of our favorite stories, and an update. New Mexico Tech Physicist Richard Sonnenfeld is at the Langmuir Laboratory for Atmospheric Research in New Mexico, where he is studying lightning. Richard and his team send instruments, carried by weather balloons, into thunderstorms. They’re hoping to learn more about what happens during a lightning flash something scientists know surprisingly little about.

“Weather balloons are quite impressive. They can easily get to eighty thousand feet, to the edge of space. But if you want to study storms you don't really need to get beyond ten kilometers, which is about six or seven miles.”

[ambience laboratory]

“Physics-wise, what we want to understand is as the lightning stroke occurs, where does the charge go? For example, the tip of a lightning stroke: is all the charge there? Or, as the lightning progresses, does it leave charge behind? We figure that it probably does leave some charge behind and there are some simple models that explain why lightning ought to leave charge behind. But we'd like to measure exactly what it does. And then, the models can be improved, and we can understand more about how lightning propagates.”

[ambience lightning]

Since we last heard from Richard Sonnenfeld, instruments on weather balloons have detected packets of electrical charge flowing in two directions through a lightning flash: one set headed toward the growing tip of the lightning, and another set generated at that tip and propagating backwards. Until now, this occurrence had never been observed in lightning.

Pulse of the Planet’s Science Diaries are made possible by the National Science Foundation. I’m Jim Metzner.