Coppery/iron-like smell in the air after it rains?

April 6, 2007 8:21 PM

Where I grew up in a suburb of LA, a coppery/iron-like smell, reminiscent of pennies or blood, would always waft unpleasantly through the air after it rained. I could never locate its source. Has anyone else had this experience, and what causes this?
posted by shivohum to science & nature (18 comments total)

Where in LA are we talking about?
posted by Methylviolet at 8:29 PM on April 6, 2007

It's difficult to pin down without more information. It might be the sulfuric acid in the rainwater reacting with either the soil, or building materials used in your area that have some sort of copper additives or otherwise something that has a smell resembling copper.
posted by Burhanistan at 8:36 PM on April 6, 2007

Yes, I am familiar with this, and I grew up in Virginia. In particular, I recall the earth smelling copper-ish after a brief summer rain.
posted by killdevil at 8:38 PM on April 6, 2007

Grew up in Jersey, and I always smelled this after a spring/summer shower. I always just associated it with warm weather rains, especially quick, heavy showers.
posted by backseatpilot at 8:45 PM on April 6, 2007

Interesting answers so far.

Where in LA are we talking about?

Near Pasadena...
posted by shivohum at 8:50 PM on April 6, 2007

Your description brings to mind a short summer rain in salt lake city. I didn't find it unpleasant, and wouldn't have described it as you did, but now that I think of it, I can see the connection

Apparently the smell metal is actually an organic compound
posted by Good Brain at 8:51 PM on April 6, 2007 [1 favorite]

Also, for what it's worth, the "coppery" or metallic smell you associate with pennies isn't really the smell of metal at all. It's the scent of various organic compounds... apparently some ketones are implicated.

This is based on some research that came out and made the rounds of news organizations last year... maybe somebody else can come up with a better citation.
posted by killdevil at 8:58 PM on April 6, 2007

jinx
posted by killdevil at 8:58 PM on April 6, 2007

Also, if you noticed this smell after thunder storms it could just be the newly released ozone in the air blending with the usual air pollution. Do you recall if this happened during rain storms with little or no lightning, or only when there was noticeable lightning?
posted by Burhanistan at 8:59 PM on April 6, 2007

I grew up in Sierra Madre -- and now live in Long Beach.
The air after a rain did smell different, I think. My parents explained it as "dissolved smog."
posted by Methylviolet at 9:13 PM on April 6, 2007

I have kind of the opposite thing... I always lived in Southern California up until now so I know that smell as normal. For 2 years I've been trying to figure out why the post-rain air smells so much different in the Bay area. I just figured that maybe it's because there's less polution where I live now.
posted by miss lynnster at 9:52 PM on April 6, 2007

I'm in Canada, and I've lived in England, and what you've described is "the smell after rain." I've smelled it everywhere, but more often after a short, sharp rain than a prolonged storm.

Possibly another language actually has a word for it.
posted by Dipsomaniac at 9:53 PM on April 6, 2007

I know the smell you're talking about. But it seems to me that I only notice it after the first rain after a dry spell. I always thought it was caused by splatter of the rain kicking up the dirt and oil off the street. After the first rain, the dirt and oil have been washed away so you don't have the smell after subsequent rains. When it's dry for awhile the dirt and oil have a chance to accumulate and the next rain kicks them up again.

At least that's my explanation.
posted by ShooBoo at 10:31 PM on April 6, 2007

Petrichor(wikipedia) is a word for the smell of rain on dry Earth.

I remember having an argument with a friend in high school who maintained, perhaps in jest, that it would be impossible for that to have a smell because rain is water and water doesn't have a smell. Haha.
posted by KevCed at 2:43 AM on April 7, 2007

I'd always heard it explained as being ozone in the air.
posted by blasdelf at 3:28 AM on April 7, 2007

Do you recall if this happened during rain storms with little or no lightning, or only when there was noticeable lightning?

No recollection at all, unfortunately.

Petrichor(wikipedia) is a word for the smell of rain on dry Earth.

But is this always coppery?
posted by shivohum at 6:22 AM on April 7, 2007

i always thought it was the smell of ozone, produced by lightning hitting oxygen, and pulled down to nose-altitude by raindrops.
either that or the fishy bloody smell of worms getting squshed on the sidewalk. but it's a familar and not entirely unpleasant smell in ontario, where i grew up.
posted by twistofrhyme at 10:45 AM on April 7, 2007

I live near the mouth of a river that runs through agricultural areas and this coppery/pungent smell is extremely overpowering after a heavy rain, while the river and surf is running brown. I suspect it has something to do with agricultural runoff.
posted by Manjusri at 11:43 AM on April 7, 2007