I love this smell. I've been fighting with the wife, who claimed it was from asphalt, and I knew it wasn't, since I've smelled it in the middle of nowhere. Turns out, she was actually pretty close, since it's hydrocarbon based.
Somebody should make a perfume based on this. It should be possible to extract the specific oils responsible.
I love this smell too. Smells are emotionally charged to begin with, and this is one of the more powerful ones in my experience. The fact that it's so intermittent and fleeting (small correction to the title: it's the smell after it's just begun to rain) adds to its mystery. Because of that, I kind of hope it doesn't get extracted into a product. Perhaps I'm being too nostalgic, though, sitting in just about the darkest day of winter when it's been -20 for most of the past month...
According to the wikipedia spanish article for Petrichor, they haven't been able to synthesize the smell due to its complex composition of more than 50 substances.
I've always been able to smell something distinctive BEFORE it rains. Don't know what causes that, but I've always thought it was actually change in air pressure that my nose is misinterpreting as a smell.
Are you thinking of a smell with a kind of sharp, metallic or chemical odor, right before a heavy thunderstorm?
If memory serves me, that's due to the voltage between the storm and the ground turning O2 molecules into O3 (ozone), which gets spread around by the storm's winds.
That is, in fact, ozone. You're not alone. I often smell it ahead of big storms as well. Of course, I also smelled it after watching the maple tree in my front yard get zapped 20 feet away with nothing but a window screen and air between my face and $DEITY knows how many kilovolts.
There is some variation in how sensitive people are to individual odors. Picking up the ozone smell before storms seems to be sufficiently rare that a lot of people end up wondering if they're the only one.
Anyway, as I said, the ozone is produced by the electrical activity in the storm--if you're curious, you can get a smell of ozone off of artificial sources of high-voltage electricity as well. Hanging around a Tesla Coil or Van de Graff Generator ought to do the trick.
And hey, look at it this way, it's not the storm itself you're noticing--you're actually smelling lightning. How cool is that?
I've always been able to smell this before a storm as well. I remember when I was a kid and I would tell my parents, friends, whoever, this fact and they would just think I was crazy because no one else could smell it.
I have very poor eyesight, so my hearing and sense of smell are extremely acute.
"He holds degrees in mathematics, biomedical engineering, medicine and surgery. He has also studied astrophysics, computer science and philosophy. He has worked as a physicist, labourer, roadie for bands, car mechanic, film-maker, hospital scientific officer, biomedical engineer, TV weatherman, taxi driver and medical doctor."
He also written a ton of books and won an Ig Noble prize for his extensive research in to belly button lint colouring.
He is clearly totally awesome.
Anyway, petrichor is old news to listeners of his radio show, as it's been discussed there numerous times. I highly recommend listening to his podcast, it's full of all sorts of random sciencey stuff presented in an easy to digest way:
As this involves rain and earth, This poem immediately springs in the mind.
The red earth and pouring rain.
Red earth and pouring rain[1]
What could my mother be
to yours? What kin is my father
to yours anyway? And how
Did you and I meet ever?
But in love
our hearts have mingled
as red earth and pouring rain
Isn't it strange that so very few smells have their own words to describe them? Supposedly, there are thousands of them, but, with the exception of the formula "it smells like X", almost without exception they don't have proper names.
It's like that tribe in South America somewhere that didn't have words for colors, except in expressions as "colored like the sun" etc.
I think it's exactly because smells are so specific that there are few "general" smell words. It's useful to have a word for "red" since lots of different things are red, and particular shades of red rarely trigger very specific memories. But most of the time, when you smell something, your brain immediately tells you: it's the smell of X, for some specific X.
Presumably this has something to do with the underlying biology. Our colour space is more or less three-dimensional because we have three kinds of receptor in the eye (I'm ignoring the rods here since they aren't involved in colour vision); there are thousands of different kinds of receptor in the nose.
On the other hand, there are many many receptors of each kind in the eye; perhaps shape would be a better analogue for smell. And indeed most of our shape words are for quite specific shapes. There are some broader ones -- smooth, spiky, convoluted, etc. -- but likewise there are a few broader terms for describing smells -- pungent, musky, musty, sweet, etc.
I knew we sprayed bananas and tomatoes to ripen during transit to market but never figured plants used the same technique to delay a process (spraying the ground with an oil) to retard seed germination until it rains. Pretty neat if I read the article correctly.
I don't think that the article infers that but it could be a plausible explanation for the effect of the oil seeping out but it could also be that the moisture seeps out first and then when there is none left the oil seeps out as a last resort.
I sort of doubt plants have much to do with the smell. I used to live in a basement apartment with lots of exposed brickwork and a shitty heating system. Every Fall when the temperature started dropping, there would be moisture condensing on the brick, and it would give off the "rainy earth" smell.
Depending upon where on earth you live, I think it's possible that you haven't smelled this smell. I now live in the Pacific Northwest. I rarely smell it here, and I miss smelling it. It has to be a hot summer rainstorm, not a winter drizzle.
The smell you're describing, I think, is just "wet earth smell", which isn't nearly as pleasant.
I have never heard any one who has ever said that they do not like this smell. I wonder what is it in the that makes us so refreshed and happy. My spirits just sore at this smell.
I've never heard the term "October rain" before, but had to look it up. Quite a few poems with that title it seems. I thought you were referring to the Gun N' Roses song "November Rain" there for a second :)
Somebody should make a perfume based on this. It should be possible to extract the specific oils responsible.