We saw some good showers pass through many of our communities this afternoon. Did you smell them? Or maybe you smelled the rain this morning when the lighter showers passed through. It's a scent that's hard to describe, but humans seem to like it. There are candles made to smell like "summer rain" and "afternoon thunderstorm," but what are you really smelling - does rain have a smell?
Yes and no. Some people say they can smell rain coming; that is likely ozone they are smelling. Strong downdrafts in a thunderstorm bring down air from higher in the atmosphere containing O3. This can also be smelled after a thunderstorm passes and is often described as pungent and sweet-smelling. However, this doesn't happen every time it rains. More than likely what you're smelling is petrichor. Oils from plants, mainly leaves, accumulate during dry weather. The first time it rains, that rain disturbs the oils that have settled into the ground, pavement, and plants. The term was coined in 1964 by two Australian researchers, Bear and Thomas, for an article in the journal Nature and is constructed from Greek, petros, meaning ‘stone’ + ichor, the fluid that flows in the veins of the gods in Greek mythology.
There's another option that you smell when it's been raining for a while. Geosmin is the earthy smell most of us think of when we think of rain. It's usually strongest when it's been raining for a while, and it's created by microorganisms in the soil dying. This is linked to petrichor, but they're not the same thing.
