I stepped outside this morning and immediately knew that a large cold front was heading my way. Although the temperature was still relatively warm, the air already carried the distinctive crisp smell of fresh snow. What causes that unique scent? Snow is nothing more than frozen water, yes? So why does winter air smell so different from a tray of ice cubes? How come my memory doesn’t conjure the same nostalgiac associations of snowmen and Christmas every time I open up the icebox?
I can only find something for rain, but maybe something similar happens with snow.
http://www.madsci.org/posts/archives/1998-08/897083302.Ch.r.html
or maybe this,
http://en.allexperts.com/q/Meteorology-Weather-668/smell-snow.htm
The bigger question to me would be how you are able to smell molecules that haven’t yet reached your nose. How would the snow smell be able to outrace the cold front?
My guess would be that you are detecting other things that happen in advance of the cold front’s arrival. The nose can detect humidity and temperature; perhaps you are processing these things subconsciously with other cues like cloud formation. Perhaps snow always comes from the north, where the paper mill is located. Or perhaps it’s just confirmation bias?
Whether snow has a smell or not is something people debate - I personally side with those who say it does not. However… I saw on a science forum that some believe the “smell” people believe they detect is rather an absence of everyday smells, but there wasn’t a good explaination of why there would be such an absence that leads to the air being purer just before snow or rain.
WAG: It only snows when it’s cold, and smells are less volatile at lower temperatures.
There must be more to it than that. It’s been cold daily since November, and people don’t claim they smell snow every day. Not to mention that, while not impossible, it generally doesn’t snow once it’s really really cold…is there a threshold for how much less volative smells are in the cold? Like it being 2F is no different than 22F because it can’t effect it any more past a point?
Just to be clear, we are talking about the smell of yet-to-arrive snow, correct? Not “Wow, we must have gotten two feet last night, just smell it!”
FWIW, in my largely snow-poor part of the country, there are those of us who can detect certain changes in the weather … well, let me say it this way … as if they were smells. I believe it to be a combination of changes in humidity, air pressure, and what the wind is blowing around, if anything. What I grew up calling the “smell of snow in the air” has a totally unique dry, crisp, yet dense sensation which I distinguish primarily from the dry, crisp, but very light sensation of a brisk fall day.
I’m wondering that too, because although I never tried to compare the two until now, my memory of the smell of ice is remarkably similar to my memory of the smell of snow.
If it helps the research effort, I suffer from anosmia (no sense of smell), yet I can fully “smell” impending snow. My wife says I’m making it up, but I do agree, you can smell snow.
It’s that burns-your-nose-hairs but in a satisfying way sort of smell, a fullness, if you will. I guess you just have to smell it to know.
I can’t smell impending snow any more than I can smell an impending traffic jam. And believe me, we’ve had a *metric boatload of snow in Ottawa thus far this winter.
*(Imperial boatload divided by 2.54)
While the volatility will keep going down as temperature drops, I have no idea if the human olfactories have some threshold limit where it doesn’t matter anymore. All my experience in the field is in trying to detect explosive residue.
Well, technically I guess I was talking about the smell of probably-will-not-arrive snow, since I live in Florida these days and it’s been decades since this area got any of the real thing. I spent my childhood in the North, though; and there is a distinctive smell that I associate with winter and fresh snow. Admittedly, I don’t have any actual snowdrifts handy to compare it with.
Yesterday when the cold snap blew through, I stepped outside and was like, “Wow! Snow smell!” I didn’t really expect that any snow would actually arrive where I am, so perhaps it’s more of a “winter cold-air smell which suggests the possibility of snow.” Still, I don’t get that smell when I stick my head in the freezer, so there’s something specific about cold winter air that stands out for me. Maybe my nose is just defective.
This description seems to be just what I’m trying to convey. Last week it was cold, but smelled like any other day: today it smells like there’s “snow in the air.” It never occurred to me that it might not be an actual smell. It sure smells like a smell.
WAG: It could be a combination of dropping barometric pressure, cold temperature, and other weather related things that occur before the snow hits. We think of this as a smell, because we feel it in our sinuses, and (another WAG) our brain interprets this input as a smell.