Petrichor: Slow-mo video of raindrops reveals how rain gets its distinctive smell

[link to www.washingtonpost.com]
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Petrichor: It's a great word and an even better smell — the one that hangs in the air after a rain storm. By filming raindrops in super-slow-motion, MIT researchers think they've figured out how this smell works.

It turns out that raindrops release little bursts of aerosols, or fine particles of liquid suspended in gas.Just as the aerosols released by champagne bubbles make the wine smell and taste distinctive, the aerosols released when rain hits the ground may be sending out signature smells that get carried away on the wind. The study was published this week in Nature Communications.

“Until now, people didn’t know that aerosols could be generated from raindrops on soil,” Youngsoo Joung, a postdoctoral student who worked on the research, said in a statement. “This finding should be a good reference for future work, illuminating microbes and chemicals existing inside soil and other natural materials, and how they can be delivered in the environment, and possibly to humans.”