From: Andrew 25/08/99 18:28:57 Subject: Smell of rain post id: 32658 Has anyone noticed a particular smell to the air just before it rains heavily ? Does anyone know what causes this ? From: steve(primus) 25/08/99 19:35:23 Subject: re: Smell of rain post id: 32669 There are two main smells associated with rain. The first is ozone which can be produced by lightning. This has an acrid smell. The common rain smell is a gas called petrichor. Volatiles evaporate from plants and are absorbed by rocks, concrete etc. When the rain hits the rock, the volatiles are released into the atmosphere and you smell it. This is a clean fresh smell. From: Andrew 25/08/99 19:42:16 Subject: re: Smell of rain post id: 32671 Steve, thanks. I had often wondered about the "clean" smell. The smell I was thinking of is slightly different and usually comes just before electrical storms or heavy rain, but I haven't noticed lightening in conjunction with it so I didn't think it was ozone. Also it isn't quite like the smell around photocopiers which I had been told was due to ozone, but maybe that's ozone + other chemicals. From: steve(primus) 26/08/99 5:55:19 Subject: re: Smell of rain post id: 32808 I don't know the chemical composition, I'll see if I can find out. I first came across the term in a very early edition of Ecos, the CSIRO magazine, and I have seen a few references since then. I will investigate further. From: steve(primus) 26/08/99 16:34:45 Subject: re: Smell of rain post id: 32971 Chris, the reference on petrichor is Ecos #7 February 1976 (I knew it was an early one). The story is on the back page. There's some interesting ideas there too plus a reference for further reading "Genesis of petrichor" I J Bear and RG Thomas Geochemica et Cosmochemica Acta, 1966, 30, 869-80. Cheers From: MikeE 26/08/99 17:16:40 Subject: re: Smell of rain post id: 32983 They should bottle the stuff -- it smells great and evokes good memories (Helen?). From: steve(primus) 26/08/99 20:44:20 Subject: re: Smell of rain post id: 33027 They have bottled it Mike. Evidently in Italy they have distilled it out of rocks and called it Earthscent or some such. Check out the Ecos article - it tells all! From: MikeE 26/08/99 20:55:00 Subject: re: Smell of rain post id: 33033 I'd be worried about overdosing -- what with this and the nutmeg, I'd be spoiled rotten -- how'd three (tablespoons?) of nutmeg go in a warm milk before bed tonight, with the scent of impending rain? From: geena 29/08/99 10:39:01 Subject: re: Smell of rain post id: 33556 i agree,the smell of an impending southerly change is like no other smell i can think of. From: steve(primus) 29/08/99 11:41:52 Subject: re: Smell of rain post id: 33563 With a southerly change - or any frontal system, the air mass changes. Strong northwesterly winds back rapidly to the southwest or south. Smells can change rapidly depending on what is to the northwest of you and what is south of you. (This is without considering the "smell of rain" - petrichor). In the early days of the colony there were brick pits to the south of Sydney. The Southerly Buster would pick up the red dust from the brickworks and spread it over the nascent city. The wind was called the Brickfielder for many years. From: geena 29/08/99 12:29:57 Subject: re: Smell of rain post id: 33570 sorry steve, but the smell i am refering to has nothing to do with what the wind picks up.the smell is the same no matter where on the coast you happen to be. From: steve(primus) 29/08/99 15:11:52 Subject: re: Smell of rain post id: 33582 In that case it's as I said earlier - petrichor. This forum is un-moderated. The views and opinions expressed are those of the individual poster and not the ABC. The ABC reserves the right to remove offensive or inappropriate messages.