BeingHuman #01 | Where Does the Smell of Rain Come From ??

You've fired up the grill, set up the volleyball net, are those dark clouds on the horizon? Don't ask your phone, your nose knows all....!    

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Hello everyone…welcome to my first official science episode in Steemit ! 

Hey guys, it’s been over a month of me joining steemit…but due to my hectic duties, I wasn’t able to give much time at this place. But since I’m free from now, I thought why not post a science post over here… So guys, moving towards the topic, have you ever wondered where does the smell of rain come from?? Well, if you are really wanting to know about this interesting topic, continue reading below…trust me, you won’t regret ! 

Did you know that our noses can sense up to a trillion different scents?? And many of them are deeply knotted to our memories and our emotions. Like your grandpa’s house, your first dog, or.....the smell of rain. Storm winds carry a collection of separate smells, but the earthy odor that comes before a storm can be traced to three chemical sources. Before a thunderstorm, you’re probably smelling ozone, which remarkably gets its name from the Greek word meaning “to smell”. The electrical charge of lightning high up in approaching storm clouds rips oxygen gas into separate atoms, some of those can reform into ozone. It’s swept ahead of the progressing storm by windy downdrafts, and down to your nose level. As rain begins to fall, a new smell emerges from the soil: the pleasingly pungent perfume we call “petrichor”.  

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Petrichor gets half its name from the ethereal essence that flowed through the veins of Greek gods and half from the stones of the Earth, which very much captures both its science, and the powerful feels I get when I smell it. When decomposed organic material is blown airborne from dry soil, it lands on dirt or rocks, where it’s combined by minerals and the whole mixture is cooked into a magical medley of molecules. Falling raindrops then direct those chemicals airborne right into your nostalgic nostrils.

When there’s no rain around, those same chemicals remain in the soil, where they signal plants to pause their roots from growing or prevent seeds from germinating when there’s no water to drink. Petrichor: it’s for the plant that’s bored of waiting . . . to sprout. Bacteria in the soil also contribute to petrichor by liberating a chemical called Geosmin, that's the same compound that provides beets their earthy flavor.  

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There’s other purposes for petrichor in addition to showering us with emotion. It thought to attract camels to desert oases, who eat up and transfer the soil bacteria across the sands. Petrichor that’s washed into rivers and lakes also appears to indicate fish that it’s time to spawn. There’s nothing like a rainstorm to ignite a little romance, I guess. So next time you smell a summer storm a-coming, take a moment to think about what that rock over there is trying to tell you…! 

References used : 

1) https://www.livescience.com/37648-good-smells-rain-petrichor.html