
What Makes Rain Smell So Good? - bigalo93
http://blogs.smithsonianmag.com/science/2013/04/what-makes-rain-smell-so-good/
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jacques_chester
I grew up in the tropics. The coming rain is easily sensed -- there's so much
rain falling that at actually drives air from the upper atmosphere downwards
ahead of it. A blast of cool, sweet air is a sign that the rain drops will be
arriving in a minute or two.

 _God_ I miss it.

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dghughes
When I had a motorcycle I could tell when rain was on the way using a similar
method.

Most of the time I could be home by the time the rain started.

If you live in a cold climate you may notice the smell of snow before it snows
especially the very first snowfall of winter. Maybe I'll create my own word
and call it pnemakruos or "ice breath"

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acabal
Petrichor is one of the great neologisms of the English lexicon. An excellent
word for an excellent, trans-cultural sensation.

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mindcrime
Never thought I'd actually see this word used outside of an episode[1] of
Doctor Who. That or maybe an episode of Jeopardy. It certainly doesn't appear
to be a well known word.

[1]:
[http://en.wikipedia.org/wiki/The_Doctor%27s_Wife_(Doctor_Who...](http://en.wikipedia.org/wiki/The_Doctor%27s_Wife_\(Doctor_Who\))

~~~
another123
I first heard it in Aesop Rock's song Tetra [1]: "surface from the cellar door
like worms into the petrichor".

[1] <https://www.youtube.com/watch?v=vkHMn8q6Jlg>

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goldfeld
"If this hypothesis is correct, then the next time you relish the scent of
fresh rain, think of it as a cultural imprint, derived from your ancestors."

This is challenging the intelligence of it's readers. I thought that was
actually the whole point of the article, and the premise rather than a
doubtful conclusion? It spends the majority of it's paragraphs discussing what
compounds the smell, which while really interesting, does not at all help
explain why it smells good. Oh, so it's some oils, so what? Oils can smell
greasy and funny. There's no such thing as a scent being inherently "good."
It's all a product of our evolution.

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firefoxman1
It also doesn't answer my main question: Why does the air smell good right
_before_ it rains. I'm sure being able to smell rain coming had evolutionary
advantages...but how does it work?

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cxseven
It's probably the smell of ozone and ions causing particles in the air to
adhere to surfaces, cleaning it like how electrostatic air filters work.

[http://www.madsci.org/posts/archives/1998-08/897083302.Ch.r....](http://www.madsci.org/posts/archives/1998-08/897083302.Ch.r.html)

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wging
Interesting that we can detect it at very small concentrations. Maybe this is
an adaptation from some proto-mammal or even earlier ancestor whose
environment had few pockets of fertile ground, and detecting this smell was a
good way to find food by homing in on high concentrations of plants. (It would
not necessarily be just for herbivores. You could be likely to find the plants
themselves, but also to find creatures who fed on plants.)

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beernutz
That part set off my BS detector actually. The article claims some humans can
detect it in 5 parts per TRILLION. Is that even POSSIBLE?

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lubujackson
More detail here: [http://www.metafilter.com/122295/The-rain-in-Spain-smells-
ma...](http://www.metafilter.com/122295/The-rain-in-Spain-smells-mainly-of-
dimethyl9decalol)

Or why not just buy it in perfume form (#020 Soaked Earth)?

<http://cbihateperfume.com/premium-accord-shop.html>

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Camillo
I've never really noticed rain to have a smell. Maybe I need to live in a
drier place and get out more.

I know this doesn't really add anything to the discussion, but if there is
someone else here who has no concept of that "sweet, fresh, powerfully
evocative smell" I don't want them to feel alone.

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aerique
Sure: my girlfriend always mentions the nice smell when it has rained while
all I smell is the nasty smell of wet concrete.

I've never noticed the rain having a nice smell but that might be because I
live (and always have lived) in a densely populated area (The Hague area in
the Netherlands).

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goblin89
Putting something into words is always a translation: a part of original idea
becomes understandable to others, the rest is lost.

It's useful to think in words, as you can effortlessly communicate your
thoughts—at a price of keeping thinking within ‘translatable’ range.

From another angle, things we can approximate verbally are tempting to think
about. But can we fully _experience_ things while thinking?

Smell of rain was one of those magical things I couldn't verbalize. Now I know
a word for it, and the mechanism by which it works. Oh well…

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rtcoms
Is there really smell of rain ? I think it's more like smell of rain and sand
mixed .

In my place here in India people generally spread water in front of their home
and shop and if there is sand it smells similar to when it rains .

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moyix
On a related note, apparently the earthy smell that appears after it rains is
caused by actinomycetes: <http://birdandmoon.com/intheair.html>

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staticfish
I have always lived in cities so have assumed in the past that the glorious
smell was something to do with water coming into contact with the
concrete/tarmac/stone around me.

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elliotlai
and also, i often wonder, what makes that grassy smell before raining?

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skeletonjelly
Sounds (smells?) like that's just petrichor from downwind.

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elliotlai
Yes I think this is it!

