“The vast amount of material blasted upwards by the volcanic eruption rapidly rose to its maximum height and expanded outward to create an umbrella-shaped cloud more than 186 miles (300km) wide. The momentum generated by the blast caused the material in the plume to continually “overshoot” into the stratosphere, generating fast-moving concentric ripples known as gravity waves, a little like dropping pebbles in a pond. The lightning appeared to “surf” these waves and expanded outward, in a pattern of 155 mile-wide (250km) rings.”
How the Tonga Hunga volcano produced the most intense lightning ever seen
https://www.bbc.com/future/article/20230713-how-the-tonga-hunga-volcano-produced-the-most-intense-lightning-ever-seen
Everybody’s gone surfin’, surfin’ HungaTongaHua..