As someone who have a quite dominant melancholic trait, I am also someone who love the rain. For me, rain is not only full of memories, but it also makes me feel a calming sensation every time I smell the scent of the rain drop touching earth.
This special scent of rain called petrichor is as if have some kind of special power to deflect any negative thinking from my brain.
As it clears my mind, I am able to calmly walking on the road of life.
That being said, sorry for this sudden melancholic words. I wrote this article while being accompanied by the rain as the sun is on its peak at noon.
Anyway, regarding to the scent of rain, the question is why is it has a calming sensation? What is the scientific explanation of this?
After some research on the internet, I’ve found that the rain is actually doesn’t have any scent/aroma/odor. The rain itself doesn’t have any taste nor scent, just like any common water. But when the rains dropping on earth (the environment), it produce the scent of rain. This scent mostly occur when it’s quite a long summer.
To be precise, Petrichor occur because of a chemical reaction between the natural oil produced by plants on the air (aerosol) and geosmin. Geosmin (C12H22O) is a compound produced by the bacteria inside the soil. The rain drop acts as a catalyst or media in this chemical reaction. The microscopic aerosol brought by the rain drop touch and spread on the soil and instantly producing the smell (petrichor).
Other than that, this particular scent can also be produced from ozone. This is usually occur in a thunderstorm, in which another chemical reaction could occur. This chemical reaction is called molecular breakdown or molecular split of the oxygen molecules on the atmosphere (ozone/O3). So if by any chance you smell the scent of rain before it rains, it just means the wind brought it to you.
Keep in mind that this scent isn’t necessarily occur wherever or whenever it rains. A big city for example, especially the ones with polluted environment. There’s also heavy rains, in which this smell won’t occur because the aerosol in the air is too little. The heavier the rains, the less aerosol being produced.
That’s the brief scientific explanation I’ve got. Hope it’ll be useful for all of us.