Tim de Chant:
Late in the day on June 13, 2005, a thunderstorm was bearing down on the city of Indianapolis. As the main cell approached from the southwest, it reared up, convection currents pushing it higher and higher until it towered over the city. Luckily for Indianapolis, the cloud threatened more than it menaced, eventually dumping just an inch of rain on suburbs and farm fields to the northeast. On the surface, it may not have seemed particularly special. But for meteorologists studying the storm, it was perfect.
What set that storm apart from others, they suspected, was the fact that it passed over Indianapolis. The fact that the city was there—the subtle but significant change it made to the texture and composition of the Earth’s surface—was enough to alter the structure of the storm. Using a model they built to test the city’s impact, meteorologists couldn’t accurately simulate the June 13 storm without Indianapolis.
As a city person, I found this fascinating!