Few scenes in nature give off menacing vibes as effectively as flashes of lightning dancing around a tower of ash being spewed angrily from the fiery maw of a volcano. It’s enough to catch the Eye of Sauron. Any scientist seeking to replicate this phenomenon in a laboratory might reasonably be asked to prove that his or her last name isn’t Frankenstein.
While the ability to make measurements high in the eruption plume has allowed researchers to learn about mechanisms that cause lightning there, the understandable difficulty of working near the vent of the volcano has kept science at bay when it comes to looking into the lower regions of an eruption. A team of researchers (none named Frankenstein) at Germany’s Ludwig Maximilian University led by Corrado Cimarelli built an experiment that allowed them to study the conditions that trigger lightning at the base of the eruption plume.
Their apparatus consisted of a tube that connected a chamber filled with pressurized argon gas and ash with a tank of air at atmospheric pressure and temperature. Where the tube meets that tank, a pair of ring-shaped antennas measured electric potential, an instrument recorded pressure, and a high-speed camera filmed the eruption at 50,000 frames per second.
via Ars Technica http://feeds.arstechnica.com/~r/arstechnica/index/~3/z_mOFbydnZA/